Sonic 3 A.I.R. (Angel Island Revisited)

Sonic 3 & Knuckles (1994) was a Mega Drive / Genesis game. Sonic 3 A.I.R. rebuilds it as a modern program with widescreen and mod support. The first full version came out on 6 April 2019 after two tech demos in 2018, and DSOGaming and GamingOnLinux covered its releases.

What it is

• A remaster on its own engine: the README describes the Oxygen Engine, which runs the game logic as scripts in Eukaryot’s own lemonscript language and emulates only the parts of the Mega Drive hardware the game needs.
• Data from your ROM: according to the manual, large parts of the game data are loaded from the original Sonic 3 & Knuckles ROM, so the download contains no Sega game data.
• Moddable: the game scripts are open source and the menus can be modded. The README credits the Sonic 3 & Knuckles disassembly as a source of information.

It isn’t a decompilation like the ports in our recompiled games list, but the result is similar: the game runs as a native program rather than inside an emulator.

Current status

The 2026 stable update notes list:

• a built-in file browser for importing mods on Android, iOS and web;
• new options, including a hint for hidden monitors;
• fixes for stuttering and glitches with software rendering;
• better Ghost Sync connection stability and new modding tools.

The remastered soundtrack is no longer bundled; the official site says it downloads from the in-game Options menu.

What you need

• Your own Steam copy of Sonic 3 & Knuckles, from the SEGA Mega Drive & Genesis Classics. The game needs the combined ROM file from it, Sonic_Knuckles_wSonic3.bin. If the Steam version is installed, A.I.R. usually finds it on Windows and Mac; otherwise it asks for the file on first start.
• On Android or iOS, a PC or Mac to copy that file to your device.
• A recent graphics driver on PC; the manual describes a fail-safe mode for older hardware.

The manual says Sonic 3 & Knuckles was removed from the Steam store on 20 May 2022, so it can no longer be bought there. The developers say they can’t help with getting the ROM, and neither do we.

Other Sonic 3 projects

• PS Vita port: an additional platform port by v-atamanenko, listed in the official README.
• Nintendo Switch: the README lists its Switch build as unmaintained.

Is it legal and safe?

• Sonic 3 A.I.R. is an unofficial, non-profit fan project. Its disclaimer says it is not affiliated with Sega or Sonic Team. It ships no ROM.
• Use only a ROM from a copy you own.
• Get it only from sonic3air.org or the official GitHub releases. The project has never charged money.

Unofficial. This page is written by an independent directory. It is not made by, endorsed by or affiliated with Sega or Eukaryot (Sonic 3 A.I.R. (Angel Island Revisited)'s author). We do not host any files, and we never link to game files, ROMs or ISOs.