OpenSA2 0.1.0-alpha.3

Newer build: 0.1.0-alpha.3.1 adds Vulkan 1.1 support for older phones and fixes the white Chao in the Chao Garden.

OpenSA2's third experimental prerelease adds a game settings screen and portrait play to the Android app, and lets the renderer start on phones whose Vulkan driver lacks depth clamping.

You must supply your own unmodified PC game installation: the version Steam sells and installs today. These downloads include recompiled game logic and the port's runtime. They contain no original game executable or assets.

What's new

Game settings on Android. The setup screen has a new Game settings button. You can turn the full-width picture off, keep the HUD at its 4:3 positions or not, choose an aspect ratio (21:9, 16:9 or 4:3) and a lower resolution for slower phones, and resize, fade, move or remap the touch controls. You can also remap the buttons of an external controller. Every setting starts at the old behaviour, and app updates keep your settings. Changes apply the next time the game starts.

Portrait play. Set the orientation to Portrait to hold the phone upright. The game is drawn at 4:3 across the upper half of the screen, and the touch controls get the space below the picture instead of covering it. Picture position moves the picture between the top and the middle of the screen. Auto-rotate follows the phone and also draws the game at 4:3, so it fits either way.

More phones start. Some phones, such as the Galaxy A05 (Mali-G52), have Vulkan 1.3 but lack the depth-clamp feature the graphics layer asked for, and the renderer could not start on them. It now starts without it and draws the same picture during play. This may also fix some phones that showed a black picture with sound; if yours still does, send the app's crash report.

Downloads

Platform	Asset	Start here
Windows x86-64	OpenSA2-v0.1.0-alpha.3-windows-x86_64.zip	Extract the entire ZIP and run OpenSA2.cmd.
Android arm64	OpenSA2-v0.1.0-alpha.3-android-arm64.apk	Install the APK over the earlier one; your imported game and saves stay.
Linux x86-64	OpenSA2-v0.1.0-alpha.3-linux-x86_64.deb	Install with sudo apt install './OpenSA2-v0.1.0-alpha.3-linux-x86_64.deb', then launch OpenSA2.

Setup instructions and requirements

Windows requires Windows 10 or later and a Vulkan or Direct3D 12 graphics driver. Android requires Android 10 or later, a 64-bit ARM device, and a Vulkan 1.3 driver. The Linux package requires Ubuntu 24.04, Debian 13, or a compatible newer distribution with Vulkan graphics.

Known problems

• Phones whose graphics driver offers only Vulkan 1.1, such as one with an Adreno 610 or 644, can't start the renderer yet; the setup screen warns about this. An AYN Thor stops at the SEGA logo.
• Controller remapping was tested with virtual controllers on the desktop player, not with a real controller on Android.
• Broad stage, boss, story-event and game-mode coverage is unfinished. Widescreen menus and overlays still need work.

Tested scope

The Android APK passed, in an Android emulator: installation over earlier builds with the settings kept, a session at the default settings that matches alpha.2.1's, portrait, landscape at 4:3 with resized, faded, moved and remapped touch controls, auto-rotate turned mid-session, and the full-width picture and the 4:3 HUD turned off. Portrait and the picture position were also checked on a Galaxy S25 Edge. With depth clamping turned off, the renderer drew all 15,709 frames of the Metal Harbor replay exactly as with it on, and the emulator drew the intro the same way. The Prison Island movie still plays through to Pumpkin Hill. The Windows ZIP passed an isolated installation and startup under Wine, the Linux DEB passed an isolated installation and startup, and both desktop builds matched the boot replay. These checks cover the exercised paths only.

Thanks

Thanks to everyone who asked for these changes and reported the problems behind them: on Reddit u/StevenMX1 (better touch controls and ultrawide support), u/Glittering-Rip9556 (keeping the touch controls out of the way when playing with a gamepad) and u/darknightgamer93 (running well on slower phones); on GitHub @pcddlXDDD (#3, the Galaxy A05 report that pinned down the depth-clamp failure); and u/No_Cod_4703 and u/Gooberty_Gooby_Studi on Reddit for the black-picture reports. Thanks as well to everyone sending crash reports from the app.

Source, licenses, and checksums

SHA256SUMS records the downloadable files. The project source for all three packages is at this release tag. The public source-build bootstrap remains incomplete and still needs locally generated game inputs.

Original project code is GPL-3.0-only. Packages preserve the licenses and notices for their bundled components. Original game rights remain with their respective holders. OpenSA2 is independent of SEGA and Sonic Team.

Report a problem. On Android, use the app's Report on GitHub button. Keep game files and recordings containing game data out of reports.