🌋 Alchemy

Alchemy is a decompilation of the Game Boy Advance games ☀️ Golden Sun: The Broken Seal and ⚓️ Golden Sun: The Lost Age.

Progress

The Broken Seal is fully rebuilt from this repository, in Japanese, English, German, French, Spanish, and Italian. The Lost Age is in progress, but the parts not yet rewritten still come from your own cartridge dump.

<img src="https://alchemy.pascalpixel.com/PROGRESS_CHART.png" width="838" alt="How much of each game's code and data is rebuilt, day by day since 16 July 2026" />

Documentation

<a href="https://alchemy.pascalpixel.com"><img src="https://alchemy.pascalpixel.com/guides/docs/introduction.png" width="838" alt="The front page of Alchemy's documentation, with its World and Battle sections" /></a>

alchemy.pascalpixel.com explains how The Broken Seal works, written from its rebuilt source, with recordings from the game itself.

Build

INSTALL.md has the commands for Linux, macOS and Windows. Every build is checked against the original cartridges’ hashes in rom.sha1.

Why

Hi, I’m Pascal Pixel, an engineer recovering from a burnout. Golden Sun is my favorite game and I wanted to know how it works, so I’m decompiling it with AI agents.

Acknowledgements

Golden Sun, its characters, music, art and original code were made by Camelot Software Planning and published by Nintendo. Alchemy is an unofficial fan project, and neither company is involved with it or endorses it.

Thank you to:

• Everyone on r/GoldenSun, for cheering Alchemy on and keeping the love for these games alive.
• Tarpman and Karathan, who worked out the compiler and flags Camelot used.
• Coaltergeist, for camelot-gcc, the compiler Alchemy first built with.
• pret, whose decompilations set the standard Alchemy measures itself against, and whose agbcc builds the games’ sound and save code.
• Simon Lindholm, for decomp-permuter, which Alchemy Devtools reimplements in Rust.
• mGBA, whose libmgba plays the builds for every picture and recording in the documentation.