SM64 GBA is a non-profit fan project which aims to make a port of Super Mario 64 (along with new features, like new characters) for the Game Boy Advance The project was started as a means of testing and improving how 3D games can be developed for the Game Boy Advance architecture, a capability that only a few commercial games made use of
The game is still in development, but isn't currently intended to be released officially by the creator
