Specs: i5 2400 (3.1ghz) 12gb Ram 1gb AMD 6970 Results: Amazing I'm dual booting with Bootcamp into Windows 7. The game runs absolutely incredible - if you had concerns/questions whether or not your similar iMac could run this - fear not. The only thing I can say is the machine gets HOT - but I guess that's to be expected. If you're considering purchasing and you're running a similar setup - go right ahead. You won't be disappointed with how it performs. The gameplay/story - well that's all up to the individual.