I was getting a black screen, no music or gauntlet pointer and nothing would happen when hitting command+F. I didn't have an external monitor connected either. However I found I can get the game to launch if I manually locate the steam game files an launched from there. Weird because I already had the steam overlay turned off. Some sort of issue with Unity and Steam?
2010 Macbook Pro
2.66 GHz, Geforce GT 330M 512mb, 8GB
OSX 10.10.2