Complete - stable, without any major disadvantages (minor bugs, usually shared with Windows, still present)
Incomplete - stable, but with caveat of 1 or more minor/optional features being unsupported (compared to Windows)
Limited - playable, but with caveat of at least 1 major feature being unsupported (may not cause crashes, but major enough to notice degradation)
Broken - not in state, where game could work for normal play (crashes during basic gameplay, core gameplay bugs)