The (steam version of the) game works out of the box on my MBP (core 2 duo 2.33, ATI Radeon X1600 ). The game sometimes crash while loading the title page (either when launching, or when exiting the game).
There are rendering issues: all transparent materials mess up the rendering which can be really annoying at times (for example at the end of the basic brains level). No settings seemed to solve this misbehavior (and I wonder if this might be related to the fact that the game provides its own DirectX dll, though I know nothing about DirectX, nor about the way crossover deals with it).