Play Golden Sun and Golden Sun: The Lost Age as one game: both on a single Game Boy Advance cartridge, with your party carried over automatically from the first game to the second.
This is a free fan project. It contains no game files — you create the cartridge yourself from your own copies of the two games (see LEGAL.md).
⚠️ Early release — please keep backups of your save file. Golden Sun had to be moved inside the cartridge. That moved Golden Sun was tested with a complete playthrough (English: every chapter, side quests, final battle and credits), which matches the original game step by step, and with all maps and battles in all five languages. Saving, the start menu and the switch to the second game are tested too. The Lost Age runs unchanged, but has not been played through on this cartridge yet. If you run into anything odd, please report it.
- 🎮 Two games, one cartridge — no switching between ROMs.
- 📖 One continuous story — when Golden Sun's credits end, The Lost Age starts right away as Chapter 2.
- 🧙 Your party carries over — Isaac's team joins Felix with their levels, Djinn, items, equipment, coins and names, just like the original transfer between the two games.
- 🔌 No link cable, no second Game Boy, no password — the transfer happens on its own.
- 💾 Separate saves — each game keeps its own save files on the same cartridge.
- ↩️ Play either game any time — a start menu with Continue, Chapter 1 · Golden Sun and Chapter 2 · The Lost Age.
- 🌄 New start screen — Golden Sun's original intro and music, flowing into a view from Mt. Aleph to the Jupiter Lighthouse.
- ✅ Nothing cut — both games are complete and unchanged.
- 🌍 English, German, French, Italian or Spanish.
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Your own copies of both games as ROM files (
.gba, or.zipfiles containing them), in the same language:- English: Golden Sun (USA/Europe) and Golden Sun: The Lost Age (USA/Europe)
- German: Golden Sun (German) and Golden Sun: Die vergessene Epoche (German)
- French: Golden Sun (French) and Golden Sun: L'Âge Perdu (French)
- Italian: Golden Sun (Italian) and Golden Sun: L'Era Perduta (Italian)
- Spanish: Golden Sun (Spanish) and Golden Sun: La Edad Perdida (Spanish)
A ROM file is a copy of a game cartridge. You make it from your own cartridge with a cartridge reader (for example GBxCart RW or GB Operator). This project does not provide ROMs.
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A computer with Windows, macOS or Linux.
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An emulator to play, for example mGBA (free), or a flash cart.
1. Install Python (free, needed once): download it from python.org/downloads and install it. On Windows, tick "Add python.exe to PATH" at the bottom of the first installer screen.
2. Download this project: click the green Code button at the top of this page → Download ZIP, then unpack the ZIP file (for example onto your Desktop).
3. Copy your two ROM files into the roms folder inside the unpacked folder. .gba or .zip files are both
fine, and the file names do not matter.
4. Double-click the build file for your computer:
| Windows | macOS | Linux |
|---|---|---|
Build (Windows).bat |
Build (macOS).command |
build-linux.sh |
The first start takes about a minute to set itself up. A window then shows which games were found and builds your
cartridge in a few seconds. If your computer asks whether to run the file: on Windows choose More info → Run
anyway; on a Mac right-click the file → Open → Open; on Linux choose Run (or start it in a terminal with
./build-linux.sh).
5. Play: open the new file golden_sun_collection_en.gba (German _de, French _fr, Italian _it, Spanish
_es) in an emulator
such as mGBA — File → Load ROM. Keep the .sav file that appears next to it: it holds the
saves of both games.
Something not working? The build window tells you what is wrong (for example a missing or damaged ROM file). More help, and the manual way with typed commands: BUILDING.md.
The start menu only chooses which game starts; you then pick your save file in that game's own title screen, as usual.
| Menu entry | What it does |
|---|---|
| Continue (appears once you have saved) | Starts The Lost Age if it has a save, otherwise Golden Sun |
| Chapter 1 · Golden Sun | Starts Golden Sun — load any Golden Sun save or start again |
| Chapter 2 · The Lost Age | Starts The Lost Age — load any Lost Age save or start a new game |
So once you are playing The Lost Age, Continue takes you there, and your Golden Sun saves are always reachable through Chapter 1.
When Golden Sun's credits end, the game saves your finished game automatically (your normal Golden Sun saves are not touched), shows "Chapter 2" and starts a new game of The Lost Age. You name Felix, and Isaac's party joins your story later with everything they had at the end of Golden Sun.
Important: finish Golden Sun first, then play The Lost Age. Your Golden Sun party is copied into The Lost Age only when a new Lost Age game starts — just like in the original games. A Lost Age game you started before finishing Golden Sun keeps the standard Isaac and his team, even if you finish Golden Sun later. To play with your own party, start a new Lost Age game after finishing Golden Sun (the switch to Chapter 2 does this for you). When you save that new game, be careful not to overwrite an older Lost Age save you want to keep.
Good to know:
- Switched the game off right after "Chapter 2", before saving? Nothing is lost: choose Chapter 2 → New Game and your party is brought over again.
- Once you have finished Golden Sun on this cartridge, every new Lost Age game brings your party over automatically. Before that, The Lost Age asks about a transfer as in the original (so a password still works).
- Finishing Golden Sun again replaces the stored party with your latest run.
- Save files from the separate original games cannot be used with this cartridge.
- mGBA: works out of the box (tested).
- Other emulators: if saving does not work, set the save type to Flash 128K (also called 1 Mbit).
- Flash carts / a real Game Boy Advance: not tested yet. The flash cart must support 128 KB Flash saves.
- Codes that change items, coins, stats and the like (RAM codes) work in both games.
- Codes that change the game program (ROM codes, many GameShark/Action Replay "master codes") work in The Lost Age but not in Golden Sun.
- Only switch on cheats for the game you are playing, and switch them off before changing games — both games use the same memory for different things, so a cheat for one can break the other.
- The games' own secret button codes are unchanged and should work as usual (not all were tested).
- The moved Golden Sun was played from start to finish (automated, English). A complete recorded playthrough
(all chapters, side quests, final battle, credits and the switch to Chapter 2) is replayed on the cartridge and
matches the original game step by step (developers:
tools/playthrough/, see docs/TESTING.md). Also tested in all five languages: all 201 Golden Sun maps, all 255 Golden Sun enemy groups, saving and loading in both games, the start menu and the switch to Chapter 2 with the party transfer. The Lost Age runs unchanged and was tested at its start and with saving; a complete playthrough of it is still missing. - Small glitches are possible, mostly in Golden Sun (for example a garbled sprite), because Golden Sun had to be moved inside the cartridge. The Lost Age is unchanged. Please report where you saw one.
- Flash carts and real hardware are untested.
- Supported: the English (USA/Europe), German, French, Italian and Spanish versions. The Japanese versions are not.
- The builder shows an error: see the table in BUILDING.md — it covers wrong or damaged ROM files, mixed languages and missing packages.
- Something looks or behaves wrong in the game: please open an
issue and describe where it happened (which game, which place, what you did just before).
A screenshot and your
.savfile help. Never attach or link ROM files.
How the builder knows your ROM is correct
Every correct copy of the same cartridge is byte-for-byte identical, no matter who made it. The builder compares a "fingerprint" (SHA-1 checksum) of your file with the fingerprint of the correct copy, as listed by the preservation project No-Intro. Damaged copies or already patched ROMs are rejected; files that a reader padded with empty space or cut short at the end are adjusted automatically.
| ROM | SHA-1 |
|---|---|
| Golden Sun (USA, Europe) | 5c4695205413df7db52b9a184815a07783999971 |
| Golden Sun - The Lost Age (USA, Europe) | b500663220cb9bf56b9f8e8c0c544f1d6fa3a824 |
| Golden Sun (Germany) | c23ab91a39434623cf1a999f387d743ade1a22a6 |
| Golden Sun - Die Vergessene Epoche (Germany) | 7820b4c7ba9002b0e9be23a6f45a9ab204986438 |
| Golden Sun (France) | 42f3b262c16cfc5bde1fa2b25016fb74046de1b3 |
| Golden Sun - L'Age Perdu (France) | f14855c0f8c87a95cc52189e8e3b2bd9df186322 |
| Golden Sun (Italy) | ca45e04b26b2f040ac63e679a459d21869f5f28d |
| Golden Sun - L'Era Perduta (Italy) | 57f1d005666b81645e55412658427e27099c5907 |
| Golden Sun (Spain) | de0bdc889594b012cad213ca83707feb81ada28b |
| Golden Sun - La Edad Perdida (Spain) | a2e3e80036195343c2713410ac14f4e329e3f40d |
Finished cartridge: English d17e056a3070a467f73929bab7110eaa43425aeb,
German 90f8a4b4467083b994788e4017c46db7c361bda6, French 423f360662d4d05aeb1fdc3cf51bed7b762272e5,
Italian 3b1c876bcf8b9af3c26f2f0692e886d52c5f828a, Spanish 1c9fa0aa6cc49bdce54a6518278205633ebef906.
How it works
The Lost Age stays unchanged at the start of the cartridge. Golden Sun is moved into the upper half, and every address inside it is adjusted. A small program of our own runs when you switch the game on (start screen, menu, switch to Chapter 2, party transfer). Everything original — both games, the logo, the intro and title pictures, the music — is taken from your ROM files while building. For developers: docs/DEVELOPMENT.md and docs/TECHNICAL.md.
- Code of this project: MIT licence, see LICENSE. It does not cover Golden Sun itself.
- Third-party code and models: THIRD_PARTY_NOTICES.md (including Karanum's gs2-randomiser2, whose Golden Sun decompression this project ports).
- The middle part of the start-screen panorama was generated locally with the Z-Image Turbo image model (Tongyi-MAI, Apache 2.0) through ComfyUI, the background of the "Chapter 2" card with the MOSS-Image model (OpenMOSS, Apache 2.0) (see AI disclosure).
- Golden Sun is a trademark of Nintendo. This is an unofficial fan project, not affiliated with or endorsed by Nintendo or Camelot Software Planning. Please do not share built cartridges or ROMs (LEGAL.md).
This project was made with AI assistance, directed and play-tested by its author:
- Code, reverse engineering, tests and documentation were written with Claude Code (Anthropic's agentic coding tool) using the Claude Opus 5.5 model.
- Start screen: Claude Code also built the start screen — the code that takes the logo, the intro scenes and the music from your ROMs, the scripts and prompts for the image generation, and the choice of the generated variant. The only AI-generated image content is the middle part of the panorama (the transition between the Golden Sun and The Lost Age scenes), generated locally with Z-Image Turbo (Tongyi-MAI) in ComfyUI, and the valley background of the "Chapter 2" card, generated locally with MOSS-Image (OpenMOSS) in ComfyUI; the models, settings and prompts are documented in art/README.md.
- Everything else you see and hear on the cartridge — both games, the logo, the intro, the title scenes, the music — comes unchanged from the original games, read from your ROMs.