There are a number of things that can cause this bug. The most common are

• Broken config file(s)
  
• Fullscreen
  
• Incorrect Compatibility Mode
  
• Steam Overlay (just disable in-game overlay for SA2 in the Steam options)

BEFORE YOU TRY ANYTHING ELSE, DISABLE MODS AND VERIFY THE GAME CACHE

If the Launcher doesn't work, replace the UserConfig.cfg
(C:/Program Files (x86)\Steam\steamapps\common\Sonic Adventure 2\Config\UserConfig.cfg)
file with one containing the correct settings (use the Keyboard.cfg too for good measure):

UserConfig:
https://drive.google.com/open?id=1koWoYc22eLY9IZ6v3cBzFYXulSFhoMD9

KeyboardConfig:
https://drive.google.com/open?id=1jF10Gf9wGND73JTSkPTJ36SYA2cdH34i

NOTE: The above files are for a 1920x1080 screen running at 16:9 and 60 Hz. The controller file should work with most variations of an Xbox controller.

To fix the launcher, navigate to the Sonic Adventure 2 Steam folder, right-click Launcher.exe, and set its compatibility mode to Windows 7 or XP SP3 (Right-click, Properties, Compatibility Tab).



Run the launcher, change the settings, and make sure to uncheck "Fullscreen."

Finally, in the same folder as the launcher should be a file called sonic2app.exe. Right-click that and also set it to Compatibility Mode for Windows 7 or XP SP3 (Right-click, Properties, Compatibility Tab).


The game was originally re-released in 2012, so wasn't designed with Windows 10 in mind. By running the game in compatibility mode, the game thinks it's still in Windows 7 or XP and works fine. The config files were just missing for me (Conjecture, but I think they were never created because my launcher with all the settings that are stored in them [the config files] crashed).

Unknown (possibly an API change?)

To fix this, you need the external tool "sa2modloader,"
available here[mm.reimuhakurei.net] and here[gamebanana.com]

Guide for how to install it (you basically just drop the files in your game's folder):

https://steamproxy.net/sharedfiles/filedetails/?id=256221065

Run the mod manager, go to the 'options' tab and select "borderless window."

Do not select "Fullscreen" in the launcher. That will break the game.
UPDATE: This will work even with Fullscreen selected in the launcher. The mod manager overrides the launcher's settings.


The modloader essentially just runs the game in windowed mode, but without any borders, creating the illusion of full screen.

Edit UserConfig.cfg and set the refresh rate to 60. You will also need to set your monitor's refresh rate to 60 Hz for it to work.

Using nVidia Control Panel, you can also set the game's framerate without modifying your monitor's settings. Under the nVidia control panel, also make sure to change the configuration for refresh rate from “Global” to “Application based.”


The game was designed for this particular refresh rate, so that's probably why it won't work with any others. It was also designed to be run at a max and min of around 60 FPS.

This bug has to do with the way the game processes 'chunks' to render. Instead of loading the entire level at once, it loads only things that are relatively close to the camera. For whatever reason, on certain GPUs, the trolley gets stuck in the 'chunk' with Sonic - for the rest of the level.


Install the modloader (see above), it has a fix for this.


IDK, different from previous method

Navigate to the Sonic Adventure 2 folder (the easiest way is to right-click the game in Steam, then select 'Browse Local Files')

Rename the Launcher.exe file to something like BackupLauncher.exe

Rename sonic2app.exe to Launcher.exe.

The game probably has different settings for particular hardware, but those settings might get applied to Launcher.exe, since Steam opens that by default, and not 'carry over' to sonic2app.exe.

FIX: Music won't play unless you're connected to the Internet.

According to Steam user GoSonic, pausing and then un-pausing the game (even when offline) causes music to play again.

I guess the game might stream the music? Unknown. There is music in the game's ADX folder.