To get it to work on a mac (10.8 testes) with CX 12.1.2:
- install (I used an xp bottle)
- manage bottles -> advanced -> "enable experimental mac driver"
- run BGE Settings
- I've selected 1680x1050 (my native resolution, runs smoothly on my macpro)
- Have fun
I'ts recommendes in may posts to tweak the Advanced settings: disable antialiasing and select compatibility: SSE, Multi vertex stream, mipmapping, autogen mipmap and disable the others. but it seems also to run smoothly with full antialiasing and "autodetect".
edit: the downside of the experimental driver: alt+f4 does not work anymore (and apple-q also not)