Astro Boy: Omega Factor Recomp

Astro Boy: Omega Factor — native Windows port (gbarecomp)

A build-from-your-cartridge kit that turns Astro Boy: Omega Factor (Game Boy Advance, USA) into a native Windows program with gbarecomp, mstan's GBA static recompiler. The game's ARM/Thumb code is translated to C++ and compiled on your PC; it is not emulated instruction by instruction.

Nothing from the game or the GBA BIOS is in this kit. You supply both, and setup checks them.

What you need

• Windows 10 or 11, 64-bit, and about 2 GB of free disk space (most of it is the compiler).
• Your own dump of Astro Boy: Omega Factor (USA), SHA-1 4d652c24979dd7a08ee683b32d1d8986a5511a87 (game code BTAE, 8 MB). The European and Japanese versions, and patched or trimmed dumps, are not supported.
• Your own Game Boy Advance BIOS dump (gba_bios.bin, 16 KB), SHA-1 300c20df6731a33952ded8c436f7f186d25d3492. gbarecomp runs the real BIOS; there is no built-in replacement.
• An internet connection the first time, for the downloads below.

Install and play

Install it from the Quiver launcher, or unzip the release anywhere and run AstroBoy.exe.

The first run opens a setup window that asks for the ROM and then the BIOS, then:

1. downloads pinned, checksum-verified tools: llvm-mingw 20260616 (clang 22), CMake 3.31.12, Ninja 1.13.2 and SDL 2.32.10;
2. downloads gbarecomp's source at commit c1a5fda (tag v0.4.1) with arm-recomp-core 63dd32d and toml++ 3017243;
3. translates your BIOS and cartridge into C++ using this kit's kit/game/game.toml;
4. compiles the game (roughly 15–40 minutes, depending on the PC; it runs fewer jobs at once on PCs with little free memory).

After that, AstroBoy.exe starts the game straight away.

Command	What it does
AstroBoy.exe	Play (runs setup first if needed)
AstroBoy.exe --setup	Choose the ROM and BIOS again
AstroBoy.exe --rebuild	Rebuild the game from scratch

Controls (keyboard)

GBA	Key
D-pad	Arrow keys
A	X
B	Z
L / R	C / V
Start / Select	Enter / Right Shift
Save state / load state	Shift+F1–F9 / F1–F9
Quit	Esc

Keys can be rebound in keybinds.ini ([player1], names a b select start right left up down r l) in the game folder.

Where things are

Everything you make or that setup downloads is kept in %LOCALAPPDATA%\AstroBoy-OmegaFactor-Recomp, so updating or reinstalling the app leaves it alone:

• game\ — the built game, your ROM and BIOS copies, saves\ (the cartridge's EEPROM save) and game.log
• tools\, build\ — the compiler and build cache (safe to delete; the next run rebuilds)
• setup.log, launcher.log

Put an empty portable.txt next to AstroBoy.exe to keep all of this in the app folder instead.

Status

Played on the author's laptop from boot through the language select, title, story scenes, tutorial and the first combat stages. The configuration lists the code entry points found while playing ([[extra_func]] entries). Code in later stages that was never reached during testing still runs: gbarecomp hands it to its built-in interpreter, which can make those moments slower. Reports of places that slow down are welcome (issues on this repository); game\recomp_master_misses_BTAE.toml.frag lists what the interpreter had to run and is the most useful thing to attach.

Credits and license

• gbarecomp and arm-recomp-core by Matthew Stanley (mstan), PolyForm Noncommercial 1.0.0. Setup downloads them; the built game is made with them and may only be used noncommercially.
• toml++ (MIT), SDL (zlib), llvm-mingw.
• Astro Boy: Omega Factor is © Tezuka Productions / Sega, developed by Treasure and Hitmaker. This project is not affiliated with them.
• This kit (setup script, launcher, game configuration) is MIT; see LICENSE. It was made with the help of an AI coding assistant.