Odrannnn/MetroidPrime2Port

Echoes Unbound is a source port of Metroid Prime 2: Echoes, built on the PrimeDecomp decompilation and rendered through Aurora (SDL3/WebGPU) rather than an emulator. It is aimed at people who own a GameCube or Trilogy copy of the game and want enhanced controls, graphics and save tools on modern hardware. It is a pre-release, and the author asks users to report issues.

What playing it requires

No game assets ship with the project, in the repository or any release: you must supply your own disc image, and the port reads assets from it. Accepted discs are USA GameCube (G2ME01), PAL GameCube (G2MP01) and Trilogy USA/PAL (R3ME01/R3MP01), in formats including .iso, .gcm, .rvz, .wia, .gcz, .ciso and .wbfs; anything else is rejected as an unsupported disc. Prebuilt downloads exist for Linux (x86_64/aarch64, including AppImage and Flatpak), Windows, Apple-silicon macOS, Android arm64, and an experimental, unsigned iOS sideload. On Linux the AppImage bundles no libraries, so FreeType, libpng and a Vulkan driver plus X11 or Wayland must come from the system. Platforms and disc variants are verified separately; the PAL and Trilogy documents describe what has been checked for each.

Two features that change how you play

Cutscene and portal-transition skipping removes the world-switching wait, and the included Debug warp cheat can swap between dark and light worlds without a portal. Save states and quick resume work alongside memory-card import/export, including Dolphin and PrimeHack card folders, so you can carry saves between this port and those setups.

A set of optional tweaks covers fast Morph, Spring Ball, lock-on toggling, scan and walk speed and more, while an Original experience switch restores retail behaviour. Rendering settings add widescreen with a widescreen-aware HUD, render scale, frame interpolation and first-person FOV. Mods can be dropped in as folders that replace disc data or single resources, and an HD texture pack is supported. The F1 overlay (Start + Back on a controller) holds every setting; settings in a bad state can be reset from it, which affects configuration only, not saves.

Building and licensing

A host build needs CMake 3.25+, Ninja, a C++20 toolchain and the -DMP_SDK_HEADERS_ONLY=OFF configuration to add Aurora; the disc is needed only at run time. The upstream decompilation build is kept intact, with port changes confined to TARGET_PC blocks. The MIT license covers the port's own platform, build and packaging work, not the game code under src/ and include/, which remains Nintendo's; the NOTICE file lists third-party terms, and the project is unaffiliated with Nintendo, Retro Studios and PrimeDecomp. The author notes that parts of the port were written with AI coding assistants under their oversight.

Project source and documentation