My system:
iMac 11,3
Intel Core i7
2.93 GHz
Quad Core
8gb Ram
Crossover Games 10.0
I downloaded this off of steam. Powered it up: it ran. I can move around, interact, and so on. I just played for a couple of minutes, but the gameplay seems crisp and smooth. After I've played for awhile, I'll submit a rank, but so far it seems great.