// the find
toggins/Klawiatura
Mario Forever with rollback netcode
Klawiatura is a C port of Mario Forever 4.0, a fan-made 2D Mario platformer, with online multiplayer for up to eight players. It is for people who want to play a platformer online with friends and don't mind handling lobby server settings and matching game versions.
- Rollback netcode (the README credits GekkoNet) is the harder choice for a platformer, because the simulation has to be deterministic enough to resimulate after late inputs. Doing that on a game that was never built for it is real work.
- It targets Windows, Linux, and HTML5 through Emscripten from one plain C codebase with CMake. The public browser build is a practical check that the port stays portable.
- The build notes describe concrete problems: the MSVC static CRT blocks heob leak checking, and Emscripten debug builds can be rejected because of yyjson's local variable count. Those are the kinds of notes people write after losing an afternoon to them.
- The restorations list ties changes to specific source versions, such as checkpoints from 4.4 and Hammer Bro fights from 5.08, so the port reads as a deliberate reconstruction of the original game's history.
- Lobby compatibility depends on an exact game version and checksum match, and mods that add levels or worlds change the checksum. The README's advice when overwriting a build is to clear your data folder, which means the failure mode is silent until someone compares checksums.
- Eight stars and two forks suggest the netcode has seen little use outside its author's group. The README does not say how desyncs are detected or recovered from, so anyone adopting this for real multiplayer has to read the source to find out.
- The Unlicense covers only the source code. The Mario characters and art belong to Nintendo, and the custom assets have community authors under terms the README does not list per asset. Forks inherit that ambiguity, and it matters for anyone who wants to ship a public build.