The given reason for that is that it is a popular game that has no native version (so no one will ask why he is porting Midnight Commander) and it does not use

The given reason for that is that it is a popular game that has no native version (so no one will ask why he is porting Midnight Commander) and it does not use much OS X API. It uses OpenGL, OpenAL, IOKit (for finding input devices), AppKit (creating window), CGL (for configuring OpenGL) and CoreVideo (for running main loop).