OpenSA2 0.1.0-alpha.1

OpenSA2's first experimental prerelease brings the 2012 PC version of Sonic Adventure 2 to native Windows, Linux, and Android runtimes.

You must supply your own supported, unmodified PC game installation. These downloads include recompiled game logic and the port's runtime. They contain no original game executable or assets.

Updated 2026-10-15: the Android APK was replaced again. It fixes two crashes that ended the game when a math function got an unusual value, such as a NaN: one at the event after a stage (the _CItan issue below) and one mid-stage in Dry Lagoon. Install it over the earlier APK; your imported game stays. The Windows and Linux packages don't have these fixes yet.

Updated 2026-10-14: the Android APK was replaced. Its setup screen now has Choose game ZIP, which opens the system file picker and imports the ZIP you select. The first APK could only check a folder copied into Android/data, which Android 11 and later keep ordinary file managers out of. If you installed the first APK, install this one over it.

Downloads

Platform	Asset	Start here
Windows x86-64	OpenSA2-v0.1.0-alpha.1-windows-x86_64.zip	Extract the entire ZIP and run OpenSA2.cmd.
Android arm64	OpenSA2-v0.1.0-alpha.1-android-arm64.apk	Install the APK, open OpenSA2, and import a ZIP of your own PC game folder.
Linux x86-64	OpenSA2-v0.1.0-alpha.1-linux-x86_64.deb	Install with sudo apt install './OpenSA2-v0.1.0-alpha.1-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 compatible Vulkan support. The Linux package requires Ubuntu 24.04, Debian 13, or a compatible newer distribution with Vulkan graphics.

Desktop builds support keyboard and controllers. Android supports touch and external controllers. The installer verifies the supplied game files and prepares a separate installation.

Experimental status

In the Windows and Linux packages, a known missing block at 0x00859AC8 in the CRT _CItan fallback can stop an event after a stage. The Android APK has the fix. Broad stage, boss, story-event, and game-mode coverage is unfinished. These packages are for testing; full-game parity is not established.

The Windows runtime has been tested on native Windows, and the packaged ZIP passed isolated installation and startup under Wine. The Linux DEB passed isolated installation and a headless title-to-menu startup test. The Android runtime has reached gameplay on a Galaxy S25 Edge and a Pixel 9 Pro; the newly signed APK passed isolated installation, game-file validation, touch input, Hero intro, and City Escape gameplay in an Android emulator. These checks cover the exercised paths only.

The desktop packages use a tested development snapshot. Android includes later performance and display changes. Widescreen menus and overlays remain unfinished, and Android performance varies with device and temperature.

The APK uses a new release signing key. An installed development APK signed with the old debug key cannot be updated directly. Back up its saves before uninstalling it. Windows binaries are unsigned.

Source, licenses, and checksums

SHA256SUMS records the downloadable files. OpenSA2-v0.1.0-alpha.1-desktop-source.zip contains the matching desktop project source snapshot. Android's project source 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 reproducible issue. Include the platform, release version, and steps. Keep game files and recordings containing game data out of reports, and remove personal identifiers from logs.