Emulating Sonic Adventure – is this a good or a bad idea?

This post discusses various Dreamcast emulators in the context of emulating Sonic Adventure on a Windows PC. You may have a different experience with these emulators and other games. This post was last updated in November 2023, and Dreamcast emulators may have improved since then.

As discussed on this blog, SADX Gamecube, SADX PC 2004 and the Steam/nextgen console versions of the game suffer from a number of downgrades in almost every area imaginable, up to the point of completely misrepresenting the original Dreamcast version. In this situation one might wonder how to get the “definitive” version of Sonic Adventure. The most obvious option is playing the game on a real Dreamcast, which is perhaps the closest to the “definitive” way to play the game. However, using real hardware has its disadvantages:

  • Obviously you need to own a functional Dreamcast and a copy of the game to be able to play it. The Dreamcast is prone to hardware problems (laser degradation, PSU) that eventually make it unable to read discs or boot at all, and the more reliable replacements (such as the GDEMU or USB-GDROM) are expensive and sometimes difficult to obtain. Unless you are a big fan of the Dreamcast and play other games on it, or use it for other purposes such as homebrew, getting a Dreamcast just to play SA1 isn’t a good investment.
  • If you play the game on anything other than a CRT or something with the native resolution of 640×480, it’s going to look terrible. Don’t be misled by people claiming that the Dreamcast looks “amazingly clean” when upscaled to 1080p/4K* – this is all relative, and even with the most expensive upscalers picture clarity is nowhere near as good as playing the game in actual 1080p or 4K, which you can do using an emulator or a modded PC version.
    *When people say that, they usually compare the Dreamcast’s video output to the likes of Playstation 2, which is indeed a lot worse. The Dreamcast is capable of outputting a native 480p VGA signal, which is the “cleanest” looking signal for that generation of consoles. There is even a hardware mod to make the Dreamcast output a “pure” digital signal through HDMI. However, no matter what you do, the Dreamcast game’s internal resolution is still going to be 480p, and no amount of upscaling and cleaning up is going to make it look as good as native 1080p that you can get with an emulator or the PC version.
    Want to see how SA1 would approximately look on your monitor/TV? Take a 640×480 screenshot from the game and blow it up to your screen’s native resolution with bilinear scaling like this.
  • You’ll have to deal with all of the criticized aspects of the original version – 30 FPS, unskippable cutscenes, the old Chao system etc. Although there are 60 FPS codes for the Dreamcast version, real hardware can’t handle it most of the time and the game will go into slow motion (you may get better results on an overclocked console). When the game does run at 60 FPS, several of the problems described here will return because some aspects of the game’s logic aren’t optimized for 60 FPS. Unlike the PC version, fixing these on the Dreamcast is much more difficult for hackers/modders. It is generally much harder to make mods for the Dreamcast version.
  • If you want to play in widescreen, there are hacks for SA1 that work on real hardware. While these hacks provide some benefits (such as an increased field of view), what they ultimately do is squeeze a widescreen image into a 640×480 frame, which is then stretched by your display to the applicable widescreen size. Needless to say, combined with upscaling to 1080p/4K this degrades picture quality even further, but it still remains a viable solution to play games in widescreen on real hardware – not only for the Dreamcast, but for other consoles too, such as the Wii.

Using an emulator can mitigate many of the above issues. For example, you’ll be able to multiply the internal resolution of the Dreamcast and play the game at 1440p. There are two advantages of using an emulator as opposed to a modded PC version:

  • Some emulators (flycast, redream) have Android builds, which means you can play SA1 on your phone or tablet, provided that it’s powerful enough to handle a Dreamcast emulator.
  • Playing the game on an emulator delivers the closest experience possible to a real Dreamcast version on PC (with enhancements), whereas SADXPC with mods may not always be accurate to the original Dreamcast game.

On the other hand, emulators have issues with SA1 that make the experience sub-optimal.

  • The biggest problem is that you won’t be able to control the character properly unless you have a sensitive analog stick with no deadzone. Some controllers, such as the X360 one, work relatively well, though they are not exactly the same as the original Dreamcast controller. Even third-party controllers for the Dreamcast will cause issues in SA1 and SA2. This nuance is described in more detail on the Miscellaneous page. For an optimal experience you would have to buy an authentic Dreamcast controller and an adapter to use it on PC, in which case you might as well buy a real Dreamcast.
    If your controller behaves similar to this (jittering when pressing all the way up/down, “round” shape of diagonal limits), you should be able to use it with a Dreamcast emulator to play SA1:
  • Emulating the Dreamcast’s order-independent transparency is a major issue. Some games look acceptable without it or with less accurate transparency sorting methods, but in the case of SA1 you’re going to need the most accurate per-pixel sorting. You need at least 32 layers to be able to play the game without noticeable visual glitches, and for maximum accuracy (particularly for particles) you would want 48, ideally 64 or more.
    Per-pixel transparency sorting is taxing on the GPU, so to be able to play the game at any decent resolution without glitches you’re going to need a powerful PC. For example, a mid-range gaming laptop from 2013-2014 is barely able to handle 1440p/32 layers on Demul, and the game is relatively comfortable to play only at 1280×960. Emulating OIT on Android is even more difficult due to limited performance of most phones and tablets, though still possible.
    Not all emulators support per-pixel order-independent transparency on all platforms. Depending on the GPU, you may be limited to per-strip transparency.

Here are some typical glitches you will see if you play the game on an emulator without OIT or with less accurate sorting (some of these may look better or worse depending on the emulator, but the general issue remains the same):

And here’s the kind of glitches you will see if the layer count for per-pixel sorting is not enough. This usually happens to particles, such as fire or smoke:

The above general issues are applicable to all Dreamcast emulators. There are also issues or nuances with each specific emulator. Let’s go through the most common emulators currently available for PC.

NullDC was an open-source emulator for Windows that was discontinued in 2013. Besides reicast/flycast that are based on it, NullDC is the only emulator that has a built-in widescreen hack (“extra geom”) that doesn’t rely on stretching the picture, which is why you can find videos demonstrating Sonic Adventure in “real” widescreen/1080p using footage from this emulator. It’s also one of the less demanding emulators, so you can run it on a weaker PC. However, the emulator itself has two issues that make it sub-optimal for SA1:
1) Lack of support for per-pixel order-independent transparency, which means the game will always have visual glitches.
2) Emulation inaccuracies causing issues with collision, particularly the issue with Sonic hopping in place and being unable to jump.
In 2013 NullDC was discontinued in favor of another emulator, reicast.

Demul is a closed-source emulator for Windows that has the best compatibility and emulation accuracy to date. It also has the best sound emulation. This is your best bet when trying to emulate SA1 as close as possible to the original Dreamcast. However, there are several nuances that are worth mentioning:
1) Demul has two GPU plugins: the “new” plugin, which is recommended for maximum accuracy, and the “old” one, which, according to the author, is hacky and has many issues. However, the “new” plugin does not allow to increase the Dreamcast’s internal resolution, and that isn’t going to change anytime soon. That makes the “new” plugin useless for those who want to play the game in anything other than 640×480, which provides no advantage over playing on original hardware. The “old” plugin allows to use a higher internal resolution and works quite well with SA1.
2) Demul needs to compile shaders to emulate specific features of the Dreamcast’s GPU, so it is prone to momentary stuttering whenever a shader is compiled*. This means the game will have noticeable hiccups several times a minute unless you’ve completed the game multiple times, exploring every corner and trying every move until all possible combinations of shaders are compiled and cached. The shaders to compile are different depending on your GPU, and changing settings (such as the layer count for transparency) will require a different set of shaders. If you play the game a lot on the same PC without changing graphical settings, eventually this will become less of an issue because Demul will build shader cache that it will reuse the next time a specific effect is used.
* This isn’t a problem with Demul specifically, many other emulators rely on shader compilation and have to deal with this problem somehow. Dolphin, for example, has a feature called “Ubershaders”, which is meant to address the stutter during shader compilation.

reicast was an open-source emulator that was originally targeting Android phones and tablets, but builds for Windows, Linux, iOS, RetroArch, openPANDORA and Ouya are also available. reicast was discontinued, but a fork called flycast is available. At the moment flycast is the most viable option for emulating SA1 with enhancements such as 60 FPS and widescreen. More on that later.

redream is a closed-source emulator for Windows, Linux, Mac OS and Android. Out of all Dreamcast emulators it’s the easiest to set up, and has the nicest GUI. Like Demul, the emulator was originally open-source, but in early 2018 it went closed source. redream is a promising emulator, but there are a few concerns when it comes to using it in general and specifically for emulating SA1:
1) You need to register on the website before you can download the emulator.
2) The free version of the emulator only supports 1x internal resolution, which means you can’t play Dreamcast games in anything other than 640×480, like with Demul’s “new” GPU plugin. The paid version costs $5 and removes the limitation.
3) There can be serious input lag.
4) Analog stick emulation isn’t very suitable for keyboard use in SA1.
5) The same point about shader compilation on Demul applies to redream, although it happens less often (this may change in the future when more features are emulated properly).
6) As of November 2023, redream has issues with SA1 stemming from emulation inaccuracy:

  • Audio emulation is still not completely accurate. This manifests in some sound effects being too loud/quiet or missing DSP effects. You can check progress on SA1 sound emulation here.

With the above things taken into account I can’t recommend redream over Demul or flycast for emulating SA1, but it certainly has the potential to become the best Dreamcast emulator for this purpose.

Recently, a new way to play emulated SA1 became available: the SA1 DC-HD project. It’s a patch for the SA1 US GDI image that adds various enhancements and improves the experience on the flycast emulator. It can be played on any platforms flycast is compatible with. Here are some improvements it adds:

  • The game runs at 60 FPS during gameplay without framerate-related glitches.
  • Widescreen hack without model clipping or HUD stretching.
  • All FMVs can be skipped by pressing Start.
  • Cutscenes can be skipped by holding B before a cutscene loads.
  • If you cannot run in a straight line with your controller/keyboard, there is a patch to fix that.
  • Minor bugfixes for some levels such as object placement, Z fighting fixes etc.
  • Better level and object draw distance.
  • Optional cheats.

This is what the game looks like with these enhancements applied:

You might also want to give the modded PC version a chance. Using the PC version has a lot of advantages:

  • System requirements are going to be much lower. Although the Lantern Engine (Dreamcast lighting) mod is quite taxing on the CPU, the game is still much less demanding than a Dreamcast emulator.
  • You can run the game at 60 FPS and use any resolution you want without performing any hacks. The Mod Loader allows the game to run in true widescreen without stretching.
  • While the PC version doesn’t have order-independent transparency (although that might change someday), the majority of transparency issues with Dreamcast assets have been fixed, up to the point that the game is visually indistinguishable from the Dreamcast version most of the time. There are still some things missing, but for the majority of people who aren’t obsessed with 100% accuracy this isn’t a problem.
  • You can run in a straight line using the keyboard or any controller, and with the input mod you don’t have to worry about your controller not being sensitive enough for SA1.
  • You can install HD textures for the majority of menus instead of having to deal with stretched 640×480 assets from the original game.
  • The debatably superior SA2B Chao system is still in the game, and you can keep using it with or without Dreamcast gardens.
  • Most importanly, you can customize the game in any way you want! The mods are highly configurable: you can toggle between SA1/SADX looks for any stage, and enable or disable various extras (such as the Casinopolis Cowgirl from the Japanese 1998 release of SA1). You can also develop your own mods that change levels, lighting, models etc.

SA1 vs SADX water

One of the more noticeable changes introduced in SADX is new water textures in some stages and the distortion effect exclusive to the Gamecube version. The Gamecube’s TEV (Texture Environment) system allows for various kinds of texture manipulation, which could be used for many things including shadows, bump mapping or, in the case of SADX, underwater effects. In a sense, the water effects SADX had on the Gamecube were quite good for their time – not rare, because some PC games already had similar effects, but certainly remarkable for the hardware level. This page is going to focus on water textures and effects in different versions of the game.

Part of the reason the seashore textures were made less vibrant in SADX Emerald Coast is the way the water is implemented. It uses additive blending in SADX, and having green seashore textures together with it would make the water look like neon lights or acid. In fact, it already looks like acid sometimes, especially in the PC version:

The main problem with SADX water is lack of consistency. The water was updated to use additive blending only in Adventure Fields, Emerald Coast and the Chao Gardens (and not everywhere in the gardens – for example, in the Mystic Ruins garden the water in the background uses a “normal” blending mode, while the water in the garden itself is “acidic”). The rest of the game uses Dreamcast water textures and it looks jarring. For example, in the following area the Dreamcast version uses the same water texture as Twinkle Park, Lost World and Hot Shelter. In SADX it was updated to use an “acid green” texture, but none of the other SADX Action Stages have those water textures or use that blending mode. It makes Emerald Coast stand out among the rest of the stages. It feels as if the game was being reworked, but the developers stopped halfway. The Dreamcast version was consistent with water blending modes at least.


The main feature of the Gamecube version’s water is the distortion effect. There are two instances of the effect: distortion of things under the water surface and distortion of the whole screen when the camera is underwater. These textures are used as masks for 2D and 3D distortion:

2D distortion3D distortion

The distortion effects in the Gamecube version can look out of place in a game that hasn’t had its graphics updated otherwise. One might say the water looks more “realistic” in comparison with the more modest effect in the Dreamcast version, but the Gamecube screenshot below doesn’t look too realistic with excessive distortion. Some people may also consider it distracting because it makes it harder to navigate underwater. It gets worse when you’re moving around because the distortions are constantly moving as well. It also doesn’t work well with shadow animations on the pool sides and bottom. It could have ended up looking better if the effect was toned down a little. The Dreamcast version didn’t have distortion effects, but it still managed to convey the feeling of being underwater using a slight blue tint on the screen. The PC version has neither the distortion nor the tint effect, which makes it the worst of all three.


Some people prefer the strong distortions of the Gamecube version, others may prefer the more straightforward effect of the Dreamcast version. It’s hard to say which version is superior because in all honesty neither of the two is particularly impressive. There is a major flaw in the Gamecube version’s effect that ruins the whole “realism” part, however. The distortion occurs not only on things below the water surface, but also on things that are above it. Here’s a screenshot from Station Square to illustrate it more clearly. Look at Sonic’s head and the lamp post, which are obviously not underwater:

In fact, the game has a workaround to disable the distortion effect when the camera is too far away from the water:

To be fair, this issue is difficult to work around even in modern games. The problem appears whenever there is a non-displaced object bordering a displaced one. When a pixel is displaced, there needs to be something put in the old pixel’s place. However, if what is there shouldn’t be “warped”, you have to fill it in with something, which is usually “wrong” (special thanks to Dude for explaining the technicalities behind this). Here are screenshots from a 2017 PC/PS4 game NieR: Automata and another screenshot from Sonic Forces* with the same issue:

* The Sonic Forces screenshot was taken in an area that is not accessible normally and with a free camera mod (thanks to RobowilOFFICIAL for providing the screenshot). The artifacts are harder to see during regular gameplay.

In general it’s quite difficult to notice these artifacts in other games because level and camera design accommodates for it. However, when SADX was being ported to the Gamecube, no adjustment was done to minimize the artifacts. As a result, this common problem is more obvious in this game compared to other games.

Another problem with the distortion effect is that it makes the underwater texture animations look worse. This goes back to the argument that such effects are generally incompatible with this game’s design.


Interestingly the Steam and nextgen console ports of SADX have leftover shader code for water distortion, which suggests that the Gamecube-like water effects were being considered for the updated ports at some point. Unfortunately these effects were not implemented in these ports, so the Gamecube version remains the only version of the game with underwater distortion.

Another interesting feature about the water on the Gamecube is that it uses bump mapping. The water surface is made brighter or darker depending on the surface map that is created using the following texture:

The effect is subtle but it improves the look of the water and reduces the “acidic” colors. The PC version lacks this effect so the water is often too bright. Even if Gamecube textures are put back into the PC version, the water still looks different:

GC (bump)GC (no bump)PC

There are other differences as well: the moving pattern of the water surface is a bit more complex on the Gamecube, and the UVs make the water surface texture appear larger than on the PC version. Also, fog makes the water much brighter on PC, and in the above screenshot it’s disabled for the sake of comparison.

Gamecube underwater effects are currently being researched, and eventually you might see them in the PC version. Check this section for more information on mods for the PC version.

SADX vs SA1 extra content

Perhaps the biggest part that makes up the “Deluxe” or “Director’s Cut” branding of SADX is the new content that wasn’t available in the original Dreamcast version. Extra content adds to the game’s replay value and gives the player another chance to visit Action Stages and Adventure Fields with side quests that aren’t part of the main story. This concept works well in 3D adventure games, and it makes sense that it was attempted in SADX too. However, most of the new content in SADX is not exactly original, and often comes off as boring and uninspired. Before discussing it in detail, let’s summarize what the “DX” content offers in the following list:

  • Mission Mode: 60 mini-quests are available by starting the game in Mission Mode and picking up Mission Cards
  • Mini Game Collection (Gamecube/PC 2004 only): getting emblems and completing missions unlocks several 8-bit Sonic games that are playable via a built-in SEGA Game Gear emulator
  • Achievements and online leaderboards (Steam/nextgen consoles only)
  • Collecting all emblems unlocks Metal Sonic as a playable Trial Mode character, whereas in the original game emblems didn’t unlock anything
  • Adventure Fields have maps, which can be accessed from the Pause menu
  • There’s a Manual Camera mode that you can select in the Pause menu
  • Several times during the story you can see Cream flying around

To be fair, that’s quite a lot of extra content for just a port of an older game. It wouldn’t be a problem if it was well implemented; however, SADX seriously lacks in execution. Let’s start with the least problematic aspects of the new content and discuss some of its relatively minor design flaws:

  • The honeycomb transition used in the Mini Game Collection menus is never used elsewhere in the game, which looks jarring. The only other time the honeycomb pattern can be seen in a menu is some Adventure Field maps, but those are not animated and use a different background, and not even all maps have it. It is quite obvious that the menu was added without much care for the style of the original menus. One could argue that the original menus were badly designed anyway, which is perhaps true, but this inconsistent attempt to add a new menu doesn’t improve the overall picture.
  • The rest of the menus for extra content don’t have any transitions at all, which makes it even more jarring. For example, the tutorial for Mission Mode doesn’t have background fade animations unlike its Adventure Mode counterpart. It also clashes in style with Adventure Mode tutorials because it uses a different font and has screenshots featuring SADX Sonic and environments, whereas the tutorials weren’t updated in the port and are still featuring SA1 characters and environments. Adventure Field maps and Mission Mode stats also just pop up without any fade or zoom animation, which makes them look rough and unfinished. In the original game all menus except the pause box have animations, so it is quite easy to tell what was in the game originally and what was slapped on later.
  • The pause menu in the Game Gear emulator is inconsistent with the rest of the game. Instead of a violet rectangle it uses a rounded rectangle like the pause menu in the Dreamcast version, but its background color doesn’t match either version of the game. The buttons are also inconsistent with other menus in either game.
  • The Game Gear emulator doesn’t scale with the resolution in the PC version, which means the game will be in a small window in the center of the screen at any resolution higher than 640×480. This makes the Game Gear games nearly unplayable at higher resolutions such as 1080p or 4K. To be fair this was less of an issue back when the 2004 PC port came out, but even at resolutions like 1024×768, which were common at the time, the problem is visible. It would have been nice to have it scaled properly.
  • The Mission Mode stat screen tries to imitate the style of the Character Select screen, but fails because its fonts are visibly different and because it’s missing a fade transition.

The issues described above can be annoying to some people, but they aren’t dealbreakers and can be considered nitpicking for the most part. However, these are also indicators of the lack of effort put into the ports, including the extra content. Let’s move on to something more substantial to see how it manifests in the extra content’s quality.

The Mission system is the largest scale addition to SADX, and probably the most valuable too because it gives you a reason to revisit the stages and fields. However, the problem with SADX missions is that they are uninspired at best, and plain nonsensical at worst. This Sonic Wikia page lists all 60 SADX missions and what you need to do to complete them. There’s also a video walkthrough of all missions. Here are some examples:

Bring the man who is standing in front of the burger shop!

He is going to drown! Help the man in the water!

Lonely Metal Sonic needs a friend. Look carefully.

The burger shop statue was a funny easter egg in the original game, but the missions go way overboard in using it. While the first mission might pass as a tutorial to get the player used to the Mission Mode mechanics, the other two are simply variations of the first one: carry the burger shop statue from A to B. It is also strange how all of these missions refer to the burger shop statue as if it was a person, even though it has no animation. This would have been a nice opportunity to expand on the original easter egg, but it was wasted with poor execution.

Who is Chao a good friend with? And what is hidden underneath it? – Apart from sounding like an awkward translation from Japanese, this mission doesn’t make much sense. What’s hidden underneath what? Before you adjust to the game’s logic it may take you a while to figure out it wants you to dig next to the billboard with a picture of Cream.

I hate this dark and filthy pace!’ Can you find it? – Again, bad translation/spelling and treating Cream’s billboard as Cream herself. If it’s Cream saying that, why not have her standing there instead of the billboard? That makes more sense than her cameos in Station Square that force rotate the camera against your will so that you could see her at all, but we’ll get to those later.

Perhaps the intention was to make these missions sound ironic or humorous. There’s an opinion that part of the fun is figuring out what you have to do from vague mission instructions. On the other hand, one could also argue that mission objectives are simplistic on purpose, to appeal to younger audiences. However, compared to the game’s main quest the missions are low quality, both in terms of poor wording and variety of objectives. This is the cheapest kind of “fun” to introduce as extra content besides replaying the stages with mini-objectives, like the A/B rank missions in the original game.

There are many more examples of nonsensical SADX missions, but even with the above it is possible to notice some patterns. In general, all SADX missions fall into one of the following categories:

1. Take the burger shop statue (or a reskin of it) and carry it from one place to another.

2. Find a preset object (billboard, flag, balloon, Sonic token) and touch it.

3. Destroy X badniks and optionally go somewhere.

4. A variation of 2/3: press a button to activate a timer and destroy or collect X objects before the time runs out.

5. Collect X rings and optionally go somewhere or touch an object from 2.

6. (Big’s missions) Catch a pre-determined fish in a specific place.

On the surface these don’t sound too bad, and it was entirely possible to create, say, 20 fun and unique missions, but SADX definitely went for quantity over quality.

One problem with SADX missions is that the challenge comes not from the actual task, but from fighting the game’s buggy physics system. Many missions are made almost impossible to complete on purpose, and are incredibly frustrating as a result. For example, in Mission 53 you have to perform a series of very specific jumps, which is quite difficult – not because it is challenging, but because the physics are kind of broken. Mission 54 is only slightly less frustrating.

Some missions are frustrating because they make you fight both the physics and the camera. In Mission 58 you have to collect all flags in Lost World Act 2 while the falling rock chases after you. It is impossible to complete on the first try because you can’t even see the flags from that camera angle, so the entire mission is about trial and error. The best way to beat it is to let the rock roll down all the way and then climb back up the path you came from, fighting the camera at the same time.

We have already established that mission descriptions suffer from poor translation. In addition, they break the game’s general rule of using only two lines of text at a time. Mission Mode is the only area in the game where this rule gets broken:

The objects used in Mission Mode aren’t particularly unique: only the billboards and flags are new objects that aren’t found elsewhere in the game. SADX recycles models from the main game for mission objects: the Spinner enemy appears in a many missions, the balloon is Amy’s escape balloon, Sonic tokens use the same model as the spinning Sonic coins in Casino, and the Mission Card is the employee ID card used in the original game for getting passage to Speed Highway.

SADX missions are uninspired, frustrating, samey and unoriginal, but perhaps they’re better than nothing? Maybe, but the Dreamcast version also had extra content, and in some ways it was quite a bit richer than the lackluster Mission Mode. So let’s talk about Sonic Adventure DLCs and compare them against SADX missions.

Before discussing the DLCs, let me just get one thing out of the way. Some people claim that Sonic Adventure’s extra content requires the Dreamcast to be connected to the Internet and, because the official SA1 website went down, this content is no longer accessible. This is actually not the case. The SA1 website has been brought back online by dedicated fans, and you can access it the same way you could in 1999 – complete with monthly events you can participate in! Secondly, you can get the DLCs without connecting the Dreamcast to the Internet – by using one of the VMU backup CDs. SADX still has the advantage of having all the extra content bundled directly with the game, of course.

If you do access the SA1 website, however, it gets quite close to SADX in terms of features. There are maps for Adventure Fields, gameplay tips for each character, and the Chao Daycare system where you can upload your Chao. The site also has the Chao Black Market where you can buy rare Chao for emblems (this was the purpose of SA1 emblems all along, but the feature never worked in the US when the Dreamcast was still officially supported). But most importantly, you can get various event DLCs.

Sonic Adventure was one of the first console games to have DLCs, which were all free. After downloading a small file onto the VMU, new content was added to (or unlocked in) the game. Even though the DLCs were simple in nature, it was pretty fascinating for a 1998 game. I’ve recreated Dreamcast DLCs as a mod for SADX, so you can experience them in the PC version. In this post we aren’t going to talk about every DLC, but here’s a post that describes all of them.

SA1 had only a few DLCs, and many of them were simple decorations rather than new challenges. However, in some ways the DLCs were more unique than SADX missions. Every DLC added some unique objects, be it Reebok shoes, Christmas trees or gold rings to celebrate the year 2000. The DLCs also have some advantages to SADX missions:

1) The DLC system allows to add new assets without touching the base game. Even today it’s still possible to create custom SA1 decorations and challenges that add completely new models, textures, sounds and music without hacking the main game. A custom challenge has already been made for the original game. By contrast, SADX uses a set of hardcoded “mission objects” discussed earlier, though it can also load any object from a specific level’s object list (such as the “fugitive” in Red Mountain)*. That apart, the SA1 system is more versatile and “futureproof” than the hardcoded SADX system. While this barely matters to the player, isn’t it quite revealing that a DLC system designed for downloadable content in a 1998 Dreamcast game is technically superior to the one used in the supposedly “enhanced” port that came out on more powerful hardware 5 years later?
*Speaking of that particular mission, the “fugitive” has no animation (unlike the regular Red Mountain prisoners that are animated), and when you find him the platforms under Sonic disappear and he falls straight into the lava.

2) The timers and counters used in SA1 DLCs can work across different stages, which makes it possible to create challenges spanning across several locations (for example, the QUO DLC takes place in both Station Square and the Mystic Ruins). SADX counters and timers reset as soon as you leave the area, so all SADX missions are restricted to one act in one level.

3) Despite being simplistic overall, SA1 DLCs provide more content than SADX missions. For example, there are no SADX missions that change music (Christmas 98 and 99, Y2K, Samba GP) or unlock new Twinkle Circuit courses (Samba GP). SADX could have used that because there are five unused Twinkle Circuit courses still in the game. SA1 DLCs also change the stages a lot more – apart from decorations (that are also not found in SADX missions), SA1 DLCs sometimes add new platforms or obstacles (AT&T challenges). As basic as the DLCs are, they still seem more creative than SADX missions.

4) Even though the Steam and nextgen console versions of SADX have online leaderboards (which SA1 also had), there’s no competitive element to the missions. By contrast, SA1 events offer time challenges where you can compete with other players. At some point there were even real life prizes! Even today you can still compete against other players in those challenges if you connect your Dreamcast to the Internet (AT&T, Reebok, Samba GP etc.).

With all of the above taken into consideration, it is safe to say that SADX Mission Mode wins quantity and challenge wise, while SA1 DLCs win quality, variety and creativity wise. So in some ways, downloadable events in a 1998 game (the biggest being <50KB in size) are more varied and creative than missions in a 2003 game that had the advantage of using more powerful hardware and being able to store more extra content on the disc.

Now let’s talk about Metal Sonic. Metal Sonic is simply a Sonic model swap with one extra running animation, and it’s also broken in multiple ways:

1) In all versions of SADX except the Gamecube version his voice clips are missing. Even in the Steam/nextgen console ports, which switched back to ADX audio for voices and music.

2) When Metal Sonic is not moving, he is always leaning on a side, even when he is standing on a flat surface. It almost looks like a bug, but judging by the game’s disassembled code it is intentional. One possible reason is that the standing animation was changed to prevent Metal Sonic from saying Sonic’s idle lines after staying still for too long.

3) Metal Sonic’s afterimage effect has transparency problems with almost everything. It was supposed to look similar to Sonic’s fake “motion blur” in SA1, but it renders behind everything and ends up looking strange half the time. Here is a typical example seen when Metal Sonic is jumping on a background that has any sort of transparency:

4) Similar to the updated Sonic model, Metal Sonic has strange looking eyes in his “climbing” animation, though at least the pupils are visible:

5) Minor point, but since Metal Sonic is a robot, why doesn’t water damage him, and why can he drown? It’s just a reskin of Sonic that plays exactly the same. Instead of this addition, they could’ve implemented Super Sonic in Action Stages in SADX, especially since leftover data in SA1 indicates that Super Sonic was meant to be playable in Action Stages at some point. Thankfully there are fan-made Super Sonic mods for the PC version.

6) The Metal Sonic model is inconsistent with his other appearances in the game. SADX Metal Sonic looks nothing like the one seen in the tube at the Mystic Ruins base, or the one from Amy’s flashback. This is what Metal Sonic is supposed to look like (alternative screens from vanilla SADX PC: 1 and 2):

Instead, this is what he looks like in SADX:

The playable Metal Sonic uses the model from SA2B without accounting for the original game’s assets and design. Thankfully the Dreamcast Characters mod has an option to use the correct Metal Sonic model.

7) When you go to the character select screen after beating a level in Trial Mode as Metal Sonic, vertex welding on all other characters breaks, and you can see the seams between characters’ joints. This is quite a sad oversight because Metal Sonic doesn’t even use vertex welding. Fixing it was simply a matter of resetting the Metal Sonic flag when loading the character select screen.

To unlock Metal Sonic in SADX, you need to collect all emblems. In the original game the emblems didn’t serve much purpose (other than buying rare Chao via the Black Market website in Japan), so you didn’t have to beat all Chao races or clear all Trial missions as Big, which are commonly known as frustrating. In SADX, however, you have to beat all Big missions and Chao Races to unlock Metal Sonic and get the achievements. While this does make emblem collection more rewarding for some, it makes the game more frustrating to complete for others. But the most frustrating part is that Mission Mode and Metal Sonic are locked behind a paid DLC in the nextgen console ports. So essentially you cannot even complete the game 100% on the PS3 and Xbox 360 if you don’t buy the “DX” DLC. You also have achievements in the base game that you can’t unlock without buying the DLC.

Finally, let’s talk about Cream. We’ve already discussed strange missions featuring her billboards, but Cream herself does show up ingame. You can see her flying around Station Square after a cutscene in each character’s story:

From the above video you may have noticed that something’s off about Cream’s overall appearance. This is what she is supposed to look like:

Cream is broken in all versions of the game except the Gamecube. Her model is missing several textures and looks strangely lit up on PC and in the nextgen console ports. The function to draw Cream’s model has some buggy code, and the technical execution of the cameo is also quite strange. Instead of the traditional Dreamcast animation format used elsewhere in SADX, Cream has a separate model for each frame of her animation. Perhaps that was the quickest way to get a Sonic Heroes model to work in SADX.

To conclude, a lot of extra content in SADX appears to be poorly thought out, with questionable, sometimes outright broken implementation. Instead of extending the main game with extra content, SADX introduces new content that clashes with original designs and is overall inconsistent with the rest of the game. In several cases a Dreamcast game that came out in 1998 can pull off more impressive tricks than a supposedly “enhanced” port that came out on a more powerful system 5 years later.

Issues with SADX “enhancements”

Whenever the SA1 vs SADX topic emerges in discussion, the additional features of the port are often mentioned among the supposed advantages SADX offers in comparison to the original game. Along with added content and updated character models, these extra features are also the main reason SADX is called an “enhanced” port. Extra content aside, ultimately it comes down to the following two things:

  • The original Dreamcast game runs at 30 FPS, while SADX runs at 60 or 50 FPS depending on the region
  • In the original game you can’t skip cutscenes, while in SADX you can

Some people say they prefer SADX to SA1 because SADX runs at 60 FPS and everything else doesn’t matter. Some might argue that in a game about fast and precise movement 30 FPS is a dealbreaker. Ultimately you have to choose better visuals with lower framerate in SA1 or better framerate with poor visuals in the supposedly “enhanced” port. However, the increased framerate is a purely technical advantage that scales with the hardware the game is played on. All the developers did in SADX was untick the Dreamcast version’s framerate limiter in other areas of the game. This involved almost no programming effort because this functionality was already there in the original game and, while it’s indeed an advantage, saying SADX is better just because it runs at 60 FPS is like saying the PC port is the best version because you can run it at higher resolutions. Technically speaking it’s true to some extent – if there wasn’t a PC version, we wouldn’t have all these mods, for example. It’s fine to prefer whichever version for different reasons, but such technical advantages cannot be used as excuses to defend downgrades to the game’s visual quality and general lack of effort put into the ports. Technical stuff aside, design issues, removed effects and things like poor texture compression still stand. In addition, these technical enhancements are poorly implemented in SADX.

On the surface both 60 FPS and skippable cutscenes are unquestionable improvements. It’s certainly better to have the game running at a higher framerate, and it’s nice to be able to skip cutscenes. However, in SADX these features are inconsistent with the main game, poorly implemented or downright broken.

Let’s start with the framerate improvement. First, let’s remember that unlocking 60 FPS in this game isn’t a major technological feat per se – the Dreamcast version was originally targeting 60 FPS, but sometime during development it switched to 30 FPS. The game’s physics engine is still running at 60 FPS even on the Dreamcast, and is using mostly the same values in both versions of the game. You can still see the original version running at 60 FPS in some older Sonic Adventure promotional footage. Also, the Dreamcast version runs at 60/50 FPS in Twinkle Circuit and in the menus. SADX merely enables the already built-in functionality for the rest of the game. There are even codes to unlock 60 FPS in the Dreamcast version, although the game certainly struggles with maintaining it on the Dreamcast. It makes sense that it was disabled because even at 30 FPS the Dreamcast struggles in graphically heavy areas like Final Egg 2. Thankfully there are only a few areas in the game where that happens.

From a player’s perspective it shouldn’t matter whether the Dreamcast version had 60 FPS at some point, because the final version doesn’t and SADX clearly improves over the original, but it’s necessary to point out that unlocking 60 FPS didn’t take much time or effort on the developers’ part. Also, don’t forget that the Gamecube, where SADX originally came out, can’t always maintain 60 FPS (see: start of Speed Highway, Red Mountain), which is arguably more jarring than the more consistent 30 FPS of the Dreamcast version, so the benefit of it on the Gamecube is questionable. It’s quite possible that the large number of removed effects discussed on this blog was the result of trying to hit 60 FPS on the Gamecube. It depends on personal taste, but having to choose between lower framerate but all effects intact and a trimmed down version of the game at 60 FPS (that aren’t always consistent) is certainly a regrettable state of affairs. Also, although the gameplay can run at 60 FPS, the cutscenes are still locked to 30 FPS in SADX, which may look fine in a “cinematic” way, but now it’s jarring because the rest of the game is running at 60 FPS.

Even though the port switched to 60 FPS, the game’s internal logic was not adjusted properly for the increased framerate, which made it run at double the original speed in many cases. A lot of things that have movement or animation are twice as fast in SADX, which results in changing the game’s difficulty (for better or worse), or making certain effects less visible. There are also cases when the increased framerate causes errors in the game’s programming because the internal timers were not adjusted for 60 FPS, and as a result some things don’t behave as intended.

The most recognizable example of the game’s logic not being adjusted properly for 60 FPS is the behavior of the Leon badnik. In the original game it appears, performs a tongue lash attack and becomes invisible, only to appear again in a few seconds if the player is within its sight range. In SADX, however, Leons almost never attack the player, and prefer to disappear almost immediately, making it difficult to attack them, let alone get hit by them. In Knuckles’ Lost World it’s much more difficult to get a piece of the Master Emerald when it’s inside one of these badniks because they keep disappearing.

Here’s another example of this behavior from Windy Valley. Notice how Leon attacks the player on the Dreamcast, but tends to avoid the player on the Gamecube. This happens because the timers used in the badnik’s programming add up too fast at 60 FPS, so it doesn’t get a chance to attack before its time being visible runs out.


This isn’t the only case when the increased framerate interferes with the game’s programming. Another example is the looping engine noise you hear during the Egg Hornet boss fight. In SADX it loops too early, which makes it sound choppy. However, if you configure the PC version to run at 30 FPS, the problem magically disappears, much like the Leon issue discussed above*.

*Note that the Leon badnik is broken in three ways in the PC port: apart from the framerate issue mentioned above it’s also using hardcoded dimensions of 640×480 to determine whether it should be visible on screen. As a result, the higher the resolution the less likely the Leons will show up at all. Another issue is related to collision, which makes some badniks, including Leons, not spawn at all (this also happens on the Gamecube). The good news is that these issues are fixed in mods, and Leons now work properly in the PC version if you’re playing it with SADXFE and/or Dreamcast Conversion.

Here’s a somewhat less serious issue involving the increased framerate. Although character animations were play at framerate-adjusted speeds, the function that animates Tails’ tails was not adjusted. As a result, whenever Tails is standing still his tails move too fast. Interestingly the “flying” tail animation is adjusted with the framerate in SADX, but the “standing”, “walking” and “running” animations are not*.


*This would also make the fake “motion blur” effect on Tails’ tails harder to see, but the effect was removed in SADX altogether. More on that in this section.

Here’s another visual issue. When Sonic is inside the tornado in Windy Valley, it’s possible to see that the tornado consists of multiple layers that move at different speeds. However, in SADX the speed of each of those layers at 60 FPS is double the original speed (because the speed multiplier wasn’t adjusted for 60 FPS), so the effect disappears.


Now let’s talk about the cutscene skip feature. It often comes up as a counter-argument in the SA1 vs SADX debate because supposedly it makes the game more tolerable when replaying the story multiple times or when trying to speedrun it. Being able to skip cutscenes is a nice feature, however there are at least three things wrong with skippable cutscenes in SADX:

1) If you’ve tried to skip cutscenes in SADX before, you may have noticed that sometimes you have to press Start multiple times before the cutscene can be skipped. This happens because the game listens for user input during brief periods between things that happen in the cutscene. All of these “wait for cutscene skip” moments are hardcoded, so you can skip cutscenes only at specific moments during each of them. This feature works against speedrunners because it makes the timing imprecise. Unless you keep mashing the Start button well in advance (and even then still), your result is going to be different depending on which frame of the cutscene was playing when the game received your input to skip it.

2) Depending on the cutscene and when exactly you skip it, it’s often possible to get the camera stuck in a strange angle. Skipping cutscenes can also break some animations or cause nonsensical things to happen. For example, you can enter the temple in the Mystic Ruins before it finishes rising from the ground:

If you skip the cutscene when Sonic and Tails are landing on the Egg Carrier some weird things happen between scenes:

3) The cutscene skip feature breaks camera transitions that are supposed to take place after the cutscene has finished, and they break even if you don’t skip any cutscenes.

In the original game the camera often moves back to the player after the cutscene finishes playing. Not all cutscenes do that, and not all of these transitions are smooth, but at least the game tries to make it less jarring. In SADX, however, the camera simply cuts to the player immediately after the cutscene ends. One example of that is the Light Speed Shoes cutscene in the sewers. In the original game the camera zooms out near the end of the cutscene, so the transition is smoother. In SADX, apart from different angles that don’t necessarily work better, the camera abruptly cuts to the view behind Sonic at the end of the cutscene. Unfortunately all cutscenes are affected by this in SADX, even those where the camera transition would make sense.


In conclusion, it seems that the new content and extra features are poorly implemented and come off as an afterthought rather than a legitimate attempt to improve the game. Would you prefer to have skippable cutscenes or would you rather have smooth camera transitions? Would you play the game at (non-consistent) 60 FPS with downgraded graphics and broken game mechanics, or would you settle for 30 FPS of the original? Perhaps the most important question is, why do we have to make such choices if this is an “enhanced” port? These added features aren’t worth much considering the enormous amount of downgrades in almost every other aspect of the game. Imagine calling Sonic Genesis on the GBA the definitive version of Sonic 1 just because it added spindash and a save feature.

Thankfully you can play the PC version of SADX with mods that fix the majority of issues discussed on this page. SADXFE fixes Leon behavior, and Dreamcast Conversion introduces tweaks to the game’s logic to accommodate for the increased framerate. In addition, Dreamcast Conversion has an experimental option to restore camera transitions after cutscenes. Learn more about mods in the “Fixing the PC version of SADX” section.

Chao Garden downgrades

The Dreamcast version of Sonic Adventure was the first Sonic game allowing you to raise Chao. The Chao breeding system in SADX has many differences from the one used in the original game. There is a lot of evidence (leftover animation data, Chao Karate textures, data structure similarity and model format seldom used elsewhere in the game etc.) suggesting that the SADX Chao system is the SA2B system slapped on top of SADX engine. There are dedicated resources like the Chao Island where you can learn about Chao differences between different games, including SA1, SADX and SA2B. This blog post isn’t going to focus on smaller details like behaviors learned from different animals or new stats. Instead, here’s a list of basic differences between SA1 and SADX Chao:

  1. Chao Adventure vs Tiny Chao Garden. The original game used the Dreamcast’s VMU for a minigame called Chao Adventure. You could put your Chao on the VMU using the VMU Transporter to “take it out for a walk” in Chao Adventure, where you could increase the Chao’s stats and find different fruits. The minigame was also the only way to name the Chao and see its stats in the Dreamcast version, while in SADX you can see the stats when you pick up the Chao, and there’s a name machine in each Chao Garden. The Gamecube version has a different minigame called Tiny Chao Garden (which requires a Game Boy Advance) that has music, colored graphics and more interaction than Chao Adventure. There are different versions of Tiny Chao Garden that come with SADX, Sonic Advance and Sonic Advance 2. The PC and nextgen console versions don’t have any of the minigames.
  2. Chao Daycare vs Black Market. SADX has SA2B’s Black Market, where you can buy Chao eggs, fruits and other items with the rings you’ve collected in Action Stages. You can also get fruits from the Tiny Chao Garden. The original Dreamcast game had an online feature called Chao Daycare, which let you download other people’s Chao and upload your own Chao, and the fruits you could get from Chao Adventure. Although the Dreamcast system had a few cool features (like mating the Chao on the VMU by connecting the VMUs together, or purchasing rare Chao on the online Black Market for emblems – a Japan-only feature), a lot of people prefer the SADX system because you are no longer forced to play the minigames to get fruits that increase specific stats of the Chao, and new Chao eggs can be obtained easily through the Black Market. There are also hats for the Chao to wear.
  3. Chao variety. The original game has fewer Chao breeds. The SADX system has more variety allowing you to raise Chao of different colors and shiny/jewel combinations, as well as Hero and Dark Chao. There are also Tails, Knuckles and Amy Chao that are no longer easy to obtain legitimately. On the whole the SADX system has more genetic combinations, which makes it more fun.

Now that we’ve outlined the main differences between the Chao systems, let’s move on to the gardens themselves. The SADX Chao Gardens have some advantages over the gardens in the original game as well as some graphical improvements that don’t look too bad. For example, the water in the Station Square garden looks pretty good on the Gamecube and kind of okay (just a bit “acidic”) in the PC version. Also note how the columns have more detaled lighting in SADX.


The fountain on the Dreamcast looks empty and lifeless, while in SADX it has a Chao statue and running water. Interestingly the Dreamcast version’s SET file has a fountain object defined for this area, but it never shows up ingame. Either way, the Gamecube version has a better looking fountain.


The VMU Transporter was redesigned with the top looking like a Gameboy Advance in the Gamecube version, and like a more generic Chao transporter in the PC version (unfortunately both redesigns bear an uncanny resemblance to a squat toilet). It also has less collision issues than the original. However, the VMU-related status screen was lost, and the PC version’s unnecessary material colors give half of the machine a strange bluish tint (a similar issue to SA2B):


The Transporter has a rough-looking menu in the Dreamcast version, while SADX uses a much cleaner looking SA2B menu. The PC version looks similar to the Gamecube version except that it no longer has the “Drop off” and “Pick up” options.


The garden teleporters have received some redesign, but their effects have been removed. The transporter looks odd now without the colorful animation of the original:


Interestingly the transporter on the Egg Carrier still has the effect, although it looks slightly less vibrant in SADX because of transparency issues and different lighting.

Speaking of the Egg Carrier, the egg found in the prison cell has lost its texture and is now completely black in SADX. This is related to the change in the Chao system, where all black eggs have a solid color instead of a texture. The Dreamcast original (which is a two-tone black Chao egg rather than monotone black in SADX) looks a bit more interesting.


The palm trees have been redesigned and the basic fruit’s texture looks a bit more “cartoony” in SADX:


The palm tree redesign and the added flowers are nice, but they made the transparency issues more obvious than they would’ve been:

In the Dreamcast version, the fruit had a differently colored texture depending on how big it had grown on the tree, but in SADX the fruit’s color is always the same:



Let’s move on to the Mystic Ruins garden. From a quick look the SADX version of the garden doesn’t seem bad at all (except the sky, which looks broken in the evening and night versions). This is one of the locations where SADX uses vertex colors to really enhance the look of the scene:


The terrain and objects are lit the same way regardless of the time of day in the Dreamcast version. The original game doesn’t make use of evening and night lighting for the Mystic Ruins garden, and only changes the sky texture. This is because the Dreamcast Mystic Ruins garden always loads the day palette file even though there are evening and night lighting files for this stage. It appears to have been a planned feature that was disabled due to some issue, or just never completed. You can still see what the stage looks like with those palettes if you play the PC version with Lantern Engine and Dreamcast Conversion. In SADX the developers have split the Mystic Ruins garden’s geometry into three separate versions for every time of day, which allowed to make use of much better lighting unique to each version. This also would’ve helped a lot in Station Square or the Mystic Ruins, but unfortunately the Mystic Ruins Chao Garden is the only area in the game that has different level geometry for different times of day. Arguably it’s still less efficient than palettizing a single version of level geometry, but given that the Dreamcast version doesn’t even do that in this stage SADX is the winner here.

The water could’ve been handled better, though. The Dreamcast version uses a water texture that is consistent with the pool in the Mystic Ruins main area. The SADX texture is too transparent to be visible, although the Gamecube’s distortion effect makes up for it somewhat. The PC version’s has a strange looking water texture that doesn’t look like water, especially during the day and in the evening:


The Dreamcast version has a non-animated background water texture that doesn’t fit well with the sky, SADX attempts to fix that but it still looks a bit awkward. At night it looks almost as if there is no sea at all. In addition, the PC version’s water texture looks strange during the day:


The waterfall in the Mystic Ruins garden is different and looks a bit broken in SADX due to alpha rejection:


The Egg Carrier garden was the most buggy and strange looking garden in the original game, creating an impression that it was unfinished. Some level geometry around the seashore didn’t stick together, parts of the sea weren’t animated, the bottom of the sea had strange textures and the collision was a bit wonky. In the Gamecube version the seashore received a much cleaner look, with green vertex colors instead of sea wave textures, some decorations in the background and a cool tide effect with distortion. It looks better (except the color banding in the sky and the alpha rejection issue that makes the water splashes look worse – DC vs GC), but in the PC version there is a problem. As expected, it lacks the distortion effect of the Gamecube version, but what makes it even worse is that the ocean is completely static. This bug was never fixed in any later ports of the game. For a final version of the product that was re-released and shipped on several different platforms, this is quite an embarrassing oversight, particularly because it affects one of the few areas in the game that received a substantial redesign in the supposedly “enhanced” port(s).


The original version of the garden had a few problems – for example, it was possible to drown in the ocean, and sometimes it was difficult to pick up the Chao because they could swim too far. The SADX redesign of the garden fixed the above issues by making the island flatter and the ocean more shallow, which unfortunately also means the variety of terrain features is less impressive in the ports:


Finally, let’s discuss the part of the game which has suffered quite a lot in SADX – the Chao Race. Let’s compare different versions of it using the videos below:


There are many minor differences, but let’s focus on the following list:

  1. The Chao Race lobby (Chao Staduim) was playable in the original game. It didn’t serve much purpose, but it was fun to walk around the room and interact with the bowing Omochao. In SADX the interactive lobby was replaced with a non-playable room with a simple menu. The lighting was arguably much better in the original, too. There is some flickering in the SADX version of the level, and the letters making up the word “Chao Race” look awkward because of transparency errors.
  2. The menu to select the course and the Chao has a rougher appearance in the original game in comparison to the cleaner menu from SA2B, but there are things it did better. For example, each of the courses had a spinning 3D model of the corresponding jewel (pearl, amethyst, ruby, emerald). The Chao made sounds in the selection screen and reacted with emotions and animations when you selected them. This doesn’t happen in SADX.
  3. The Party Race (Multi-Entry) menu was removed in the PC version. It is now impossible to race the player’s Chao against each other.
  4. Before the final prompt to start the race, the Chao do a little dance animation in the Dreamcast version, while in SADX they do nothing.
  5. The Chao no longer have their name badges floating above them during the Chao Race. They also have two shadows that overlap each other and cause Z fighting.
  6. The “Start” and “Goal” graphics from the original are missing.
  7. Some background sounds are missing, such as the water gushing sound near the waterfall. Some sounds were replaced, for example the jingle at the start of the race is now a barely audible clap/shot.
  8. On the Dreamcast, the Chao react to obstacles and the environment around them, displaying a range of different emoticons. When they struggle in the water or fall asleep, their eye texture changes. None of the above happens in SADX.
  9. A lot of decorations are missing, such as butterflies and white flowers. SADX attemps to compensate for it by adding a dome with spinning stars and different flowers, but doesn’t look as lively as the original game. The Dreamcast version had cheering Omochao standing alongside the track – those are also gone in SADX. Interestingly the code for all these objects is still in the game, but they are never loaded because the game ignores the Chao Race SET file.
  10. In the Dreamcast version the Chao sometimes stop in a specific area to pick up toys and play with them. This never happens in SADX.
  11. The sea in the background is not animated in SADX. The parts in the foreground that do have animation look odd because the texture itself scrolls instead of a proper texture animation like in other parts of the game using that water texture.
  12. The sky texture in SADX and has severe color banding. Although the Dreamcast version also has a much lower quality version of the sky in the level’s texture archive, it uses a higher quality version in the level.

There are even more Chao downgrades (for example, the Chao generally make less sounds in SADX despite having a bigger soundbank), but the above are the most noticeable. While overall the Chao system from a newer game resulted in improvements, unfortunately the SADX Chao system conversion seems to have been implemented poorly. The gardens, however, do feature some improvements.

There are mods for the PC version to improve the experience that restore some things removed in SADX. For example, Dreamcast Conversion fixes several Chao Race downgrades, ports the original Dreamcast Chao Gardens, replaced the models for fruits, eggs, etc. More Chao restorations may become possible in the future. See this page to learn more about mods for SADX PC.

Boss downgrades

As can be seen in the Action Stage and Adventure Field sections, almost every area in the game had changes in SADX, and the bosses are no exception. In many cases the problems seen in boss battles are related to stage downgrades, but there are also several boss-specific effects broken or removed, and certain issues are specific to the PC port. This post is an all-in-one boss marathon so it’s going to be a little long, but that’s only because all bosses in the game have issues that weren’t there in the original game.

Chaos 0

This is the area you see first when you start the story, and one of the most memorable scenes in the game. Most of the downgrades to this area are the same as Station Square downgrades: for example, window reflections had the environment mapping effect disabled and are now a simple texture. Here’s an overview of the area as seen in the first cutscene:


You can see that the variety of textures is a bit less impressive in SADX, for example the windows on the police car use the same texture as window reflections. In addition, none of the glass surfaces have the distortion effect (environment mapping) that was there in the Dreamcast version. The back lights on the police cars are no longer lit up for some reason.

Also, during the cutscene you can notice that the lights cast on the ground by the police cars are no longer there in SADX:


When Sonic jumps on top of the police car, you can see that the flashers no longer have a reflective surface, and the rotating pieces inside them are missing:


Those rotating pieces are still there, but you never see them because the parts of the police car model are rendered in an incorrect order.

Finally, let’s have a closer look at the police car. The original car’s design was trying to create a cinematic look similar to this, while in the SADX version the reflections were replaced with low-resolution textures. Even the windshield has lost its textures for some reason.


Some engine changes/differences in SADX affect all areas in the game, including bosses. Right before the battle with Chaos begins, you can see that he looks slightly different in each version of the game:


The greenish glow around Chaos’ chest and torso in the Dreamcast version is added by the palette lighting system, which was removed in the ports. But the most noticeable difference is the blue coloring of Chaos in the PC version. It is caused by an oversight in the PC port, which makes the game process material colors even when it is not necessary. The console versions of the game don’t do that (but the nextgen console ports do).

The area itself is also affected by the removal of palette lighting. Along with missing window reflection effects it results in a less vibrant looking environment in comparison to the Dreamcast version:


Chaos 2

The lack of palette lighting causes Chaos to lose some detail on his torso:


As you fight this battle, you may notice that the lighting is different, but the most noticeable change is the windows. Now you can barely see the city background through them, and even when you do, it is missing one layer so the “parallax” effect is no longer there. It would still look kind of acceptable, but the added fog washes out the background in both ports:


The columns in this fight are supposed to become transparent when they are close to the camera, but this only happens on the Dreamcast. The code to make them transparent is still in the ports, but the level has these columns duplicated as static models to hide the transparent ones completely. This was most likely done to hide transparency issues with Chaos’ body overlapping those columns.


Chaos 4

The pond has lost the murky green texture and is now more transparent. The reflection effect was also toned down slightly:


Chaos has lost the green specular lighting specific to this area and looks more “generic” now, although the Gamecube’s distortion effect compensates for it somewhat. SADX also adds a visible bottom texture, which was black in the original game:


When fighting Chaos, you can also notice the green glow on rings and characters as they also use a green specular palette in the original game. It’s missing in SADX:


In the Dreamcast version the pond has a green texture while Chaos is swimming in it, but changes to a different texture when you beat him. You can see it briefly before Chaos falls into the pond and after you defeat him. This was removed in SADX.

Chaos 6

This boss has suffered mostly from lighting downgrades. In the Dreamcast version Chaos’ model used a special palette that gave it a dark, intimidating look. The Gamecube version’s attempt to recreate that is only somewhat successful, and the PC version looks the worst as always:


During the fight you may notice that the green glow on the Eggmobile and some objects is now given to Sonic instead, and something is wrong with the skybox in the ports:


The skybox is split into two pieces, and one of them is animated. This is the same as in the Dreamcast version, however in the ports the animated piece has an incorrect Y position. It’s supposed to be below the ship so that you can see it only near the edge of the battle area. However, in SADX it is placed right into the sky, creating visible seams between the animated and non-animated layers of clouds:


Perfect Chaos

This boss fight has a lot of downgrades stemming from code bugs in the game’s transparency sorting system, as well as some lighting downgrades. Let’s discuss lighting first, since it’s the first noticeable difference you see right away.

Like Chaos 6, Perfect Chaos also uses a special palette in the Dreamcast version. The ports don’t compensate for it in this case, and Chaos’ model just has no lighting as a result:


The Egg Carrier 2 model has excessive white specular lighting in SADX that makes it look strange. It looks particularly bad when the camera zooms in onto the Egg Carrier model. Lower texture quality is also quite noticeable if you look at the background.


Now let’s discuss broken or missing effects. Here is a video comparison of the scene when Chaos gets attacked by Super Sonic:


There are several problems with the scene compared above:

  1. When Perfect Chaos is hurt, he explodes into water splashes that fly all over the place. The animation for these splashes is stuck on the last several frames in the Gamecube and PC ports, which makes the whole scene less impressive.
  2. The waterfalls have a particle effect at the bottom, which is missing in the ports. Well, it’s not missing, but it shows up only a few times depending on the camera angle. This is caused by an issue with the alpha rejection system, which makes them invisible.
  3. There is some faint mist around Chaos’ location, which also randomly appears and disappears in the ports due to a bug with alpha rejection. More on why that happens in the Transparency section. Most of the time you just can’t see it.
  4. When Chaos emerges from the water, the tornadoes around his body fade in slowly in the Dreamcast and Gamecube versions. In the PC version they just pop in.
  5. On the Dreamcast the tornadoes around Chaos’ body have animated UVs that make it look like the tornadoes are spinning in opposite directions. The animation is still there in SADX, but it’s harder to see which direction the tornadoes are spinning because the animation is choppy. This is caused by two things: 1) the animations have been simplified in the ports 2) the animations themselves are faster because of the increased framerate in the ports.

Let me also briefly mention the Super Sonic model. His body has lost the environment mapping effect and is now using a static yellow texture. The distortions created by the environment mapping effect react to camera changes, but the yellow texture always looks the same.


Egg Hornet

Apart from losing palettized lighting like the Mystic Ruins, the Egg Hornet battle has some other changes. For example, the metallic “reflections” on the Egg Hornet model are less vibrant in the ports because SADX has the environment mapping effect toned down:


When the Egg Hornet attacks Sonic, it rotates as if it’s digging the ground. This works fine in the original game and the Gamecube port, but the rotations are missing in the PC port:


Egg Walker

This boss fight was updated to reflect the changes made to Station Square, but the cars in this area are still using their shiny Dreamcast models as opposed to the updated SADX models you can see in the Adventure Field. However, the most noticeable problems with this boss are 1) lighting on the Egg Walker model and the rest of the stage, and 2) missing skybox (obscured by fog) in the PC version.


If you look closely, you can notice that the sky is slightly more purple in the Gamecube version, which is the same color as the missing skybox in the PC version. This is caused by added fog. The Gamecube version has several fog modes that allow the fog to disperse in different ways, while the PC version only has linear fog, which is why the sky is obscured completely by it.

Egg Viper

This area is suffering from major lighting downgrades and loss of detail, which are noticeable even in the cutscene leading to the boss fight, although the beginning of it doesn’t look too bad on the Gamecube. As always, the PC version is the worst of all:


This low-resolution wall texture behind Sonic wasn’t updated. This goes back to an argument made earlier that the game was only updated in areas that had rendering issues in their original designs, and the “upgrades” came out of necessity rather than a legitimate attempt to improve the experience. The lighting on Sonic isn’t too bad here though:


The area where you see the Egg Viper for the first time suffers from lighting downgrades, with the green shading missing entirely and the Egg Viper model being lit up for no reason on the Gamecube. In the PC version lighting is almost completely missing in this area.


The walls in the area where you fight the Egg Viper were changed to look more “rusty”, and the spinning dot effect behind the walls is no longer visible. The lighting was also simplified, although the Gamecube version doesn’t look too bad. The lighting on the platforms is also simpler in the ports.


The Egg Viper fight had a few unique lighting effects that barely survived the Gamecube transition and are completely missing in the PC port. But first, let’s look at the start of the fight to see the spinning dots effect in motion. You may also notice that the Egg Viper model has lost its specular glow in the ports:


One of Egg Viper’s attacks is a big explosion. This explosion also colors the walls red in the Dreamcast version. The effect is still there on the Gamecube, but it isn’t as bright. In the PC port the effect is completely missing.


A similar effect can be seen when Sonic hits the Egg Viper. This time it’s a bright red flash, which is also less bright on the Gamecube and missing completely on PC:


Another effect is seen when the Egg Viper charges a ball of plasma to attack Sonic. On the Dreamcast the walls flash blue with an increasing amplitude. This effect is broken in all ports. On the Gamecube the walls lose all lighting, and in the PC version nothing happens:


E-101 Beta

The boss area was redesigned to reflect the changes to the Adventure Field. Other than minor differences in character lighting it doesn’t look too bad, perhaps even better than the original stage. It also adds lighting to the door, which is fullbright in the original game.



Apart from issues specific to the Adventure Field where this fight takes place, there are some problems with the E-101R boss. The model loses the subtle pink specular light for generic white gloss in the ports, but the main problem with it is the issue with the glass floor, which is specific to the PC version. You can see that the particle effect has transparency sorting problems with the glass floor on PC:


When Beta does the ramming attack, the effect around his body is less vibrant in the ports. For some reason it’s blue on the Gamecube and dark grey in the PC port. If you look closely, you can see that the Dreamcast version of the effect is properly textured, while the SADX version is not:


Some texture quality downgrades happened with the textures used for ZERO and E101R boss fights as well. It is particularly visible on explosion and “rainbow shield” textures. Here is a brief comparison:

Click the following links to compare textures in their original quality:
ZERO: SA1, SADX Gamecube
E-101R: SA1, SADX Gamecube

As you can see, all bosses have downgrades in SADX, and the boss fights that were the most impressive on the Dreamcast (Chaos 0, Egg Viper, Perfect Chaos) have suffered the most. The Dreamcast Conversion mod resolves all issues discussed here. Visit this page to learn more about SADX mods.

Sky Chase downgrades

Unfortunately even the minigames (subgames) received some downgrades in SADX. Much like the rest of the game, they suffer from worse lighting, poor texture quality, transparency problems and model issues. Sand Hill also has some sound problems, such as certain sounds playing too quietly or missing altogether. This page is going to focus on Sky Chase since this minigame has received some of the more noticeable visual changes.

In the PC version, Sky Chase is broken at resolutions higher than 640×480. It becomes more obvious at 1080p or 4K. It’s difficult to control the Tornado because of increased acceleration that gets multiplied together with the resolution. Some enemies don’t fire at higher resolutions (because their programming uses hardcoded dimensions of 640×480), so it’s much more difficult to get emblems that require a high score.

On the other hand, the minigame is also much easier on PC. In all versions of the game it’s possible to get through Sky Chase 1 and 2 without dying by simply holding up+left throughout the stage. In the second act you will reach the “boss” mini-fight with less than half of your energy on the Dreamcast. In the PC version, however, if you stay in the top-left corner at 1080p, you will get to the same point with just two hits.

The character models used in Sky Chase were updated in the ports. During gameplay the original game uses low-poly models that look like something out of Sonic R, even though higher-poly models are used in Sky Chase-related cutscenes. SADX updates all Sky Chase models with Sonic and Tails onboard the Tornado.


However, the lighting on the Tornado is more basic than in the original game:


One of the first things noticeable in this stage is that the Egg Carrier is not visible immediately in Act 1. Instead, it gradually pops in as you progress through the stage. This is most likely caused by reduced skybox scale in the ports, which makes the skybox obscure the Egg Carrier model. If skybox scale for Act 1 is set to the same value as in Act 2, the Egg Carrier is visible from the start, like in Act 2.


Another issue you can see in the screenshots above is layering of the sky. The Dreamcast version had smooth transitions between the static clouds and the animated bottom of the skybox, but in the ports the transition is sharper with noticeable color banding. This is caused by transparency order problems and lower texture quality in the ports. In addition, the PC version’s unnecessary processing of material colors gives the bottom of the skybox a dark gray look, a problem similar to what happened to the clouds in Red Mountain Act 1. In this case it doesn’t look too terrible, but this isn’t the way it was supposed to look. The Gamecube version doesn’t have this problem.

The transition issue also affects the second act, which is less noticeable on screenshots, but still quite visible in motion. The sky textures fade to black smoothly on the Dreamcast, while the Gamecube and PC versions have a clear border separating skybox pieces:


Another issue is with the Tornado’s reticle. On the Dreamcast it has a smooth appearance, while in the ports it looks pixelated. Let’s compare them at 640×480 since the vanilla PC version doesn’t support scaling, and to demonstrate that it’s clearly visible even at low resolutions*:


*On top of that, as the reticle is not scaled at higher resolutions in the PC version, it is harder to lock on enemies because the reticle uses the same hit detection as it would at 640×480.

The Egg Carrier model used in this level is slightly different from the original. The part with the green glass floor has a washed-out look to it. To be fair, that part of the model was also given a higher polygon count so the area looks a bit rounder as a result:


The above difference is especially noticeable in the second act, which uses the same Egg Carrier model:


What’s interesting is that the Dreamcast model of the Egg Carrier works fine as-is when imported into SADX. It doesn’t have the problem the updated model has. So it might have been changed to look less colorful on purpose, or the updated model piece didn’t get proper UVs.

The sun flare textures look pretty bad in all versions of the game, but compression artifacts are more noticeable in the ports:


In all versions of the game the effect for the giant laser beam goes behind the clouds at the bottom, but the ports make it look worse, especially the PC version:


The texture used for this effect has noticeable quality degradation, especially in the PC version. It is also mirrored, however here it is also one of the few cases where the mirrored texture has a higher resolution:

In Act 2 the lighting on the Egg Carrier no longer has a yellowish tint in the Gamecube version. In the PC version the lighting is almost completely gone and the background looks noticeably worse because of poor texture quality.


As you can see, the only improvement SADX introduces in Sky Chase is the updated character models. Everything else is plagued by various issues, much like the rest of the game. The minigame is almost completely broken in the PC port when it’s played at higher resolutions. However, the good news is that all issues discussed on this page have been fixed in mods. A while ago a more correct scaling system for Sky Chase was developed for the Mod Loader. Original lighting is restored in SonicFreak94’s Lantern Engine mod, and the transparency issues are fixed in Dreamcast Conversion. You can even get the original character models for Sky Chase using ItsEasyActually‘s Dreamcast Characters mod, and you can select between the low-poly models or the higher poly models used in cutscenes!

To learn more about SADX mods, visit this page.


This section lists differences and problems with the port(s) that don’t fit into other categories, as well as discusses several misconceptions about SA1 flaws.

Title screen, menus and branding

The Dreamcast version had an animated Sonic Team logo with an ocean background (click the image to get an animated gif). In SADX it was replaced with a static Sonic Team logo. Not a big deal, but how is this better than the original?


The title screen is also different between versions. The Japanese and original US releases of Sonic Adventure had a static image with a stylized “Sonic Adventure” logo. The “PressStartButton” text was static in the Japanese version, but the US version added a fade animation. The International release added an animated ripple effect to the background and changed the logo slightly:

Sonic Adventure US
Sonic Adventure International

SADX replaced the ripple effect with a scrolling background, added a render of Sonic and made the logo more generic. You can still see the original title screen in nextgen console ports if you don’t buy the “DX” DLC.

The Pause menu received a slight redesign in SADX. Now it tells you which mode you’re playing (Adventure, Trial or Mission), removes shadows and uses a smaller font. SADX also adds Adventure Field maps and an option to switch between automatic and manual camera, both of which are nice additions. However, the visual changes are somewhat less impressive. The rounded corners of the background rectangle were removed, and gradients everywhere except the buttons were disabled. The buttons were also made blue instead of teal. Both versions look kind of generic, but is the SADX one really better?


Intro movie and FMV cutscenes

Let’s discuss the intro movie and FMVs. This is a bit unusual because out of all versions of the game the Gamecube version has the best quality intro movie. The Dreamcast version’s intro resolution is 320×448, and the video gets stretched horizontally to 640 with black borders on top and bottom to make it 640×480. The FMVs are even lower quality – 320×256 stretched to 640×480. The Gamecube version has the same FMVs as the original game, but the quality of the intro video is noticeably higher, with better bitrate and it’s already 640×448 so it doesn’t need horizontal stretching. One difference with the new intro is the logo transition, which lost the background animation and became more generic. Click each image in the comparison below to see an animated GIF:


Interestingly the 2004 PC port is a bit special in this regard. Its intro and FMVs are in true 640×480 without black borders, which means the PC version’s intro has more visible details than the Dreamcast and Gamecube intros. The Steam and nextgen console versions use the same FMVs as the Dreamcast/Gamecube (the intro is different though, but let’s discuss that later). As a result, the 2004 PC port has the best looking FMVs:

PC 2004

The 2004 PC port has the best quality FMVs, but the same can’t be said about the intro. Although the intro itself is in 640×480 without black borders, it suffers from poor compression. The Steam and nextgen console ports have intros based on the PC one but recompressed, so their quality is even worse. Below you can see clickable comparisons of the same frames extracted from each version’s intro movie:



PC (2004)

Playstation 3/Xbox 360


The winner here is the Gamecube version, while the Dreamcast version looks worse or close enough depending on the scene. The 2004 PC version looks worse than Gamecube, sometimes even worse than Dreamcast, and the Steam/nextgen console ports have the worst looking intro movie out of all ports. Let’s not forget that the Steam/nextgen console ports also have the lower quality FMV cutscenes from the Dreamcast version, even though the higher quality ones were in the 2004 PC port they are based on.

The nextgen console ports have an intro movie featuring the “original” SA1 logo. This would’ve been a nice homage to the original game (if we forget for a moment that those ports try to fool you into thinking they ARE the original game), but the animation for the logo transition lacks some effects and isn’t very faithful to the original. Although the logo itself looks clearer in the new intro, the original intro has a better animation. In addition, the nextgen console intro is slightly messed up – when the letters zoom out, the image is cut off on the right, which makes the letters C and E look strange.


A closer look at the intro movie (props to Speeps and McAleeCh for discovering this) reveals some interesting details. It appears that, despite the higher overall quality, the intro movie in all ports is based on an earlier, unfinished version of the video similar to the intro seen in a prototype version of Sonic Adventure known as the “Autodemo”. The SADX intro has more in common with the Autodemo than the final Dreamcast intro, which has different details and appears more complete overall. This post by McAleeCh documents the process of recreating the SA1 intro in higher quality from several sources, and is great read if you’re interested in detailed differences between various versions of the intro. For now, however, let’s focus on the most noticeable parts.

The majority of Station Square shots in the SADX intro look like the Autodemo intro, while the final Dreamcast version uses shots from Super Sonic’s story. For example, in the following shot the Gamecube version is missing some fog/lighting details like the Autodemo:

Similarly, the intro on the Gamecube is missing some pedestrians, and the cars in this scene are arranged differently:

The following shot crossfades with different timing in the SADX intro. Although it doesn’t look “bad” per se, it’s clearly more like the Autodemo rather than the final version:

A notable difference is Tails’ expression in the intro. It’s also clearly from the Autodemo:

Finally, here’s one more interesting detail about the SADX intro. The numbers on Gamma’s body are simply slapped on (the Autodemo intro doesn’t have them at all), while in the Dreamcast version they have lighting and are consistent with the shape of Gamma’s body:

With all the above examples there’s little doubt that the SADX intro is based on an unfinished version of the final game’s intro. Thankfully it isn’t an exact copy of the Autodemo’s intro. The Autodemo’s intro is 320×240 stretched to 576×480 with black bars on each side to make it 640×480, so at least a higher quality source was used for the SADX intro.

Another thing about SADX that feels unfinished is the FMV skip feature. On the Dreamcast you could only skip the Sonic Team logo and the intro movie, which is somewhat annoying. In SADX you can skip all videos by pressing Start or A, which is nice, but unlike the original game the skipped videos don’t fade out – instead they just cut immediately. Interestingly SADX does have a system for fading out videos, which is used on all videos except the intro movie (where it’s deliberately broken and the fades are built into the video file itself). This system could’ve been used easily to fade out videos when they’re skipped, but for some reason it isn’t implemented. Minor point, but it’s just another example of where the original game did better.

Aspect ratio on the Gamecube

The Gamecube version of the game is rendered at an incorrect aspect ratio. While this was usually corrected automatically by older TVs, it’s difficult to get the game to scale properly on modern TVs and video capture hardware. Even on an emulator the aspect ratio is wrong, and the picture appears slightly squished horizontally. Here’s an image from Sonic Retro that uses footage captured from real hardware. Even though the zoom is different, you can still clearly see that Sonic is noticeably taller in the Gamecube screenshot in comparison to the PC version that uses the same Sonic model. You can also tell the aspect ratio is incorrect by the shape of the letter A in Amy’s name:

Subtitle font differences

One of the better known differences between SA1/SADX Gamecube and the PC version is that the PC port no longer uses the “Impress” subtitle font, but there’s more to it. Here’s a comparison of how the subtitle font looks in different versions of the game at the original resolution (top: Dreamcast, middle: SADX Gamecube, bottom: SADX PC):

There’ve been claims that the subtitle font color is inaccurate on Dreamcast emulators, and that the font is supposed to be white on real hardware. This has been proven false – the font is not white on the Dreamcast, it uses a subtle dark gradient and is slightly transparent.

The Gamecube version’s text looks a bit more washed out even though it’s the same font. It appears to have some kind of smoothing or texture filtering applied. It’s either an aspect ratio artifact, or it’s using font smoothing like in the PC version. More on that below.

SA1 and SADX Gamecube use the “Impress” font for English and the “Comic Sans” font for other European languages. There’s also a separate font for Japanese. Each of these fonts comes in a separate file that is loaded depending on the current language setting. In the PC port the font system was reworked, and a single font file is used at all times. The updated font is smaller and looks more washed out than the Dreamcast version. Let’s have a closer look:

Even when the original font in reimplemented in the PC version, even with original SA1 font data it doesn’t look right:

It appears that the PC version (and possibly the Gamecube version) applies a slightly transparent outline around the letters, which makes the font thicker and a bit harder on the eyes:

Disabling this feature made the subtitles look a lot better, even with the original SADX PC font.

Other minor differences

Here’s a minor, but interesting difference: all lines, such as Gamma’s laser scope or Big’s fishing line, are thicker on the Dreamcast.


Is SA1 a barely playable buggy mess? Yes and no.

For many years Sonic Adventure has had the reputation of a buggy game. There are many issues stemming from the game’s wonky collision system and weird camera behavior, which was not uncommon for games at the time. Landing between platforms closely stuck together or spindash spamming into a wall can sometimes make Sonic clip through walls or fall through the floor. While these are definitely annoying, is Sonic Adventure unplayable because of such issues? Not really.

SA1 doesn’t have nearly as many game-breaking bugs as other supposedly less buggy games it’s compared with – such as Super Mario 64 or Ocarina of Time. There is a documented bug in SA1 that corrupts save files – getting the Crystal Ring upgrade in Final Story before fighting Perfect Chaos. With the game’s story taken into account, it’s a rather obscure bug that isn’t likely to happen during a regular playthrough. Other savegame corruptions may happen after glitching the characters into levels they don’t visit normally, such as Amy in Casinopolis. These glitches require fighting the game’s collision system and aren’t very easy to perform. They are unlikely to occur in regular gameplay.

Also, SA1 has no known bugs that interfere with gameplay in a fundamental way. The worst outcome of a gameplay bug in SA1 is an accidental death of the character. Sonic falling to his death on the first loop in Emerald Coast because the player didn’t hold forward is annoying, but compare that to the “Reverse Bottle Adventure” in Zelda or the glitch in Super Mario 64 that lets you skip through the whole game and beat it with 0 stars. While Super Mario 64 is a 1996 game, Majora’s Mask came out almost 2 years after the original Japanese release of SA1. In reality, all of these games are old and buggy, but SA1 is definitely not among the buggiest.

On top of that, SA1’s reputation has suffered a lot from misrepresentation by bloggers, youtubers and game journalists. Many of SA1 criticisms are fair. However, as more and more people can’t play the authentic version of the game on the Dreamcast, problems with Dreamcast emulators and pirated game rips are portrayed as inherent issues with the original game that SADX supposedly “fixed”. Some of such glitches are discussed below.

Control downgrades and issues with SA1 Dreamcast controls

Let’s talk about the controls too, since there seem to be some misconceptions about them. In the original game, you could tilt the analog stick slightly to make Sonic walk slowly, and he would walk faster the farther you pushed the analog stick. While this is still present in the ports, the analog sensitivity is a bit reduced (in the PC port at least), and depending on the controller the range between slow walking and running at full speed can be very short. In the PC version it’s fixable with SonicFreak94’s Input Mod. While this isn’t a major issue, it might affect people’s opinion on controls in this game because it messes up the already floaty controls of the original.

Some people say it’s impossible to run in a straight line in the Dreamcast game because it constantly tilts the analog controls to the left or right. This is commonly caused by emulation inaccuracies – it doesn’t happen on actual hardware (but see the note below regarding third-party controllers). The game has a bug with interpolation, but it doesn’t happen on original hardware because the Dreamcast controller has no deadzone and holding straight forward or backward creates slight analog “noise”. More information here. A less common complaint about the Dreamcast version is that you can move at insane speeds by steering the analog stick diagonally while jumping – this is also caused by the emulation issue mentioned above or by using third-party controllers.

Here is what the original Dreamcast controller’s deadzone looks like when the controller is connected using a USB adapter to PC:

Notice how it’s very easy to slip to the side slightly while holding up or down. The Dreamcast controller’s analog stick is sensitive to slight movement because it has no deadzone. Another characteristic trait of the Dreamcast controller is a diagonal movement limit – so when you rotate the stick, the shape the cursor follows is a circle rather than a square.

Here’s what a different controller’s deadzone is like:

The above video demonstrates input from another Dreamcast controller that looks identical to the original, but this one was made by a third party. This is also how most cheaper controllers behave on PC. The deadzone in this controller is more stiff, which removes the jittering “noise” while holding the stick in a straight direction, and there is no “rounded” limit to diagonal axes like in the original controller. The first deadzone difference makes Sonic unable to run in a straight line in SA1 and SA2, and the second difference makes it possible to travel at much higher speed in SA1 while jumping and holding down the analog stick diagonally.

The reason people are getting all those control issues in the Dreamcast version of the game is because they have either of the following:

1. An emulated version of the game on PC, which is still meant to be used with the original Dreamcast controller rather than third-party controllers or the keyboard. The emulators don’t fix the game’s interpolation issue that requires analog “noise”, and they don’t add a limit for diagonal axes in SA1 and SA2, which the original controller had. If you use the original Dreamcast controller (or a wired X360 controller with the emulator), these problems go away.

2. A third-party Dreamcast controller that has a less sensitive deadzone and/or no diagonal axis limit, which causes problems in the Dreamcast game similar to those experienced on an emulator with a keyboard/non-Dreamcast controller.

To sum it up, these problems do NOT happen when original hardware is used. However, they MAY happen on emulators or on a real Dreamcast when using third-party Dreamcast controllers.

The true reasons behind the infamous “sewer glitch”

One of the issues that often gets brought up is the glitch that happens in Sonic’s story after obtaining the Light Speed Shoes and makes him unable to get out of the sewers. Like the controls issue, it can happen on a real Dreamcast. There are workarounds but the issue is generally quite frustrating. However, it has nothing to do with the Dreamcast version of the game per se.

The “Light Speed Dash sewer glitch” happens in two scenarios:
1. Emulation bug involving floating point values
According to inolen, the developer of the redream emulator, there is a CPU emulation issue that can cause this glitch on Dreamcast emulators. The latest version of Demul isn’t affected. The glitch can happen on NullDC, reicast and redream (it may have been fixed in redream as of October 2018).

2. Pirated rips of the game with incorrectly patched binaries
The original Dreamcast version of SA1 came on a GD-ROM disc, which could hold up to 1GB of data. Pirates have exploited the Dreamcast’s ability to read ordinary CD-ROM discs and made “selfboot” packages that can be burned to ordinary CD-Rs and played on the Dreamcast. Such packages also removed regional limitations so you could play the game from any region on any Dreamcast console. Preparing a selfboot package involves hacking the original binary files to allow the game to boot from a CD-R. Many older scene rips of Sonic Adventure have a patched 1st_read.bin that causes the infamous sewer glitch.

Because the issue is caused by two completely different factors, it is reproducible on emulators and on a real Dreamcast, which made a lot of people assume it’s an issue with the original game. To avoid the issue, make sure to do the following:

  • If you’re playing the game on a real Dreamcast, use the original GD-ROM version of the game or a good rip, such as the DCRES rip of Sonic Adventure International.
  • If you’re playing the game on a Dreamcast emulator,
    1) Use the latest version of the emulator and
    2) Use GDI rips (which are made from original GD-ROMs), not CDI rips meant for burning.