Alchemy is a decompilation of ☀️ Golden Sun: The Broken Seal and ⚓️ Golden Sun: The Lost Age: the Game Boy Advance games written out again as readable C code, pictures, music and text, which build back into the original games byte for byte, in all six languages.
Camelot wrote Golden Sun as source code and turned it into the machine code on the cartridge. Their source was never released. Alchemy writes it again, one function at a time, and every piece is checked by compiling it and checking that the result matches the real cartridges.
With the source you can read exactly how Golden Sun works, from the damage formulas to every cutscene, and change it: rebalance it, translate it, add scenes, or build editors and ports on top of it.
- Not a remake, a mod or a PC port. It builds exactly the games Camelot shipped, unchanged, and that is all it will ever be. Mods and ports belong in projects of their own, built from it.
- Not new content. Every picture, song and line of dialogue is Camelot's, taken from the cartridge into editable files. No art, music or writing in it is AI-generated.
- Not a download. There's no installer,
.exeor ROM image. The repository holds the source code plus Camelot's art, music and text as editable files, and the build recreates the original ROMs exactly.
Alchemy is a hobby project I started in July 2026 to enjoy making things again after a burnout. I build it with AI coding assistants: they propose C code, the build compares it with the cartridge, and only what matches is kept. I direct the work, decide how the code is organized and named, and fix what doesn't match.
The code is still being cleaned up for people. Names and comments are moving into plain English, and functions nobody understands yet keep placeholder names such as sub_08012345 rather than guesses.
- The Broken Seal builds entirely from this repository, in all six languages. No ROM is needed.
- The Lost Age is in progress. It builds too, but the parts not yet rewritten still come from your own cartridge dump.
INSTALL.md has the few commands to build it on Linux, macOS or Windows. It builds these ROMs, so anyone with their own cartridge dumps can check the result:
| Language | The Broken Seal | The Lost Age |
|---|---|---|
| Japanese | 35ef9e4c9f38183ebd6a3e3923a11ce9a4333718 |
4c79e60962299654981628ccd99b122ef27043f7 |
| English | 5c4695205413df7db52b9a184815a07783999971 |
b500663220cb9bf56b9f8e8c0c544f1d6fa3a824 |
| German | c23ab91a39434623cf1a999f387d743ade1a22a6 |
7820b4c7ba9002b0e9be23a6f45a9ab204986438 |
| Spanish | de0bdc889594b012cad213ca83707feb81ada28b |
a2e3e80036195343c2713410ac14f4e329e3f40d |
| French | 42f3b262c16cfc5bde1fa2b25016fb74046de1b3 |
f14855c0f8c87a95cc52189e8e3b2bd9df186322 |
| Italian | ca45e04b26b2f040ac63e679a459d21869f5f28d |
57f1d005666b81645e55412658427e27099c5907 |
Golden Sun, its characters, music, art and original code were created by Camelot Software Planning and published by Nintendo. Alchemy is an unofficial fan project and is not affiliated with or endorsed by either company.
Thank you to:
- The r/GoldenSun community, for sharing Alchemy, cheering it on, and keeping the love for these games alive.
- Tarpman and Karathan, for identifying the compiler and flags Camelot used, and Coaltergeist, for camelot-gcc, the compiler Alchemy first built with, since replaced by agscc.
- pret, whose decompilations set the standard Alchemy measures itself against, and whose agbcc Alchemy builds the games’ library code with.
- Simon Lindholm, for the permuter whose behavior Psynergy reimplements in Rust.