Metroid Fusion
Boots, lightly testedGBA · 2002 · Action · Decompilation
Samus wakes on a research station overrun by a parasite wearing her own abilities.
Controls
| Arrow keys | move, aim |
| X | A (jump) |
| Z | B (fire, dash) |
| Enter | Start (map screen) |
| Shift | Select |
| A / S | L / R (diagonal aim, missiles) |
| Gamepad | Standard Gamepad mapping (untested) |
About this build
Metroid Fusion in the browser on a WebAssembly build of the mGBA core. The matching ROM is produced by the metroidret/mf decompilation, which is 87% decompiled and reconstructs its image partly by extracting data from your own cartridge at build time. You supply the ROM; the page reads it locally and a Content-Security-Policy of connect-src 'none' means the browser refuses every network request it could make.
- Built from
- mGBA's mCore API compiled to WebAssembly with emscripten, driven by a small C shim; no emulator frontend in between
- Type
- Decompilation
- Game files
- You supply your own Metroid Fusion (USA) ROM, 8 MB, sha1 ca33f4348c2c05dd330d37b97e2c5a69531dfe87. It is read in the browser and never uploaded.
- Code licence
- See the upstream decompilation and mGBA (mPL 2.0)
- Assets
- No retail data is distributed; every byte comes from the ROM you supply
- Source
- metroidret/mf ↗
What has been tested
Build byte-matches the staged ROM (sha1 ca33f4348c2c05dd330d37b97e2c5a69531dfe87), verified by sha1sum -c, by cmp, and after an audited clean rebuild. Browser: 40/40 automated checks, muted, ROM fed through the real file picker. Reached verified player-controlled movement in the opening room, gated on the game's own gMainGameMode/gSubGameMode1/gSamusData from the build's symbol table. The game loads its own save back across a page reload, with a corrupted-save control arm. CSP connect-src 'none' verified against six egress channels.
Last tested 2026-10-05 in Chrome 151 headless (Linux). Full playthrough: not verified. How games are tested.
Known limitations
- Not yet playable here: no hosted page has been published for this title.
- The upstream decompilation is 87% complete and is not shiftable; the build reproduces the ROM partly by copying data out of the ROM you supply, so a matching build is not the same as a fully decompiled game.
- Tested only in headless Chrome 151 on Linux. No Firefox, Safari or mobile browser.
- Play-tested only as far as the opening room: movement, jumping and one door. Nothing past that was played.
- Saving at one of the game's own save stations was never reached; save persistence is verified on the file the game writes when a new game starts, which the game does load back.
- No touch controls. The gamepad mapping is written but was never tested with a controller.
- Sound is off by default and has never been listened to; every test ran muted.
Saves
Your cartridge save is kept in this browser under the site's own storage and restored when you come back. Clearing site data removes it. Save states are stored the same way.