unfortunately I found out about this bug after purchasing it and of course steam couldn't be bothered to give me a refund for a game that flatly doesn't work on my platform.
I found this thread (http://steamcommunity.com/app/264140/discussions/0/620700960223924439/?insideModal=1) that describes my problem perfectly and refers to a fix for this issue for PC but not for MAC (1.xml etc do not exist). I have tried removing saves and even removing the game entirely but the issue persists..
... this.. this is why i hate steam games..
latest OSX yosemite on most recent macbook pro hardware 16G RAM and NVIDIA GeForce GT 750M 2048 MB