I feel your pain, This is most likely because your machine uses intel integrated graphics. (Check this by going to the apple menu/about this mac/more info/Displays and if it says something to do with intel in the graphics card info area, this fix is for you!
Go into steam and then go to launch options and when there type this code:
-dxlevel 81 +mat_forcehardwaresync 0 +mat_antialias 0 + mat_disable_bloom 1 +mat_forcemanagedtextureintohardware 0 +snd_async_prefetch_priority +mat_softwarelighting 1 +mat_reducefillrate 1 +mat_bumpmap 0 + mat_specular 0 +mat_picmip 2 +mat_max_worldmesh_vertices 1024 +map_background none -heapsize 1024000 +datacachesize 768 -autoconfig
That should get you into the game but there are still unresolved problems such as:
- When you get up to a "loading point the game crashes,
- When you die the screen goes black and doesn't let you re-spawn,
- It's very slow :(
I'm not saying that you will have these problems, you will have to try it and see.
Hope this helps! Good luck!
