There aren't as many, especially if you don't count half-assed Cider-based ports (like I'm sure WAR is). Sure, the most popular games get ported, but little else. And even if the port is coded well, performance is generally far worse than their PC counterparts because the video card manufacturers don't give a damn about Mac drivers.

Anyone who can run Cider "ports" should be using Boot Camp for games. They'll get better performance on the same hardware and have a wider variety of games to choose from.