Has anyone else's problems disappeared? I tried SMB today on my Mac running Mountain Lion and managed to play a couple of levels. Can't check further because I'm at work but I'm hoping something has been fixed. I'm running the game through Steam, but I didn't notice any updates come through (although I'm not very familiar with Steam).
EDIT. Figured out having it set to -800x600 -meddetail stops the crashes on startup. Still affected by the bug where failing in a warp zone and being kicked back to the level select crashes the game. Absolutely ridiculous how broken the mac port is. Contemplating bootcamping my Macbook just to play this game, which should be completely unnecessary if OSX is officially supported!