Bought this game on Steam when it first came out - it had an error code that kept the game from fully loading, even after deleting/redownloading it three times. So, when I saw it on the MacGameStore I figured that they must have solved the issues with it. Well, it downloaded completely, but now it hangs up at start-up. So, I've asked the MacGamestore for a refund. Again. Reading the boards, the game seems to be very unstable - some people have no problem runnning it, while others with the same Macs never get it to work. Worst game rollout ever!