waltc: Just install Win7/8 (your choice) to your Mac via Bootcamp (I'm assuming that Apple supports Windows 8 at present with Bootcamp--if not, then Windows 7 is fine but a bit more difficult to find these days)...I know you're "lazy"...;)...but the obvious benefit is that you will not be limited to OS X supporting the comparatively small number of games that it does--not to mention that most of the Mac games are ports from the original Windows/D3d games to OS X/OpenGL anyway (Valve says that Apple's OS X is now up to rough par with version 3.2 of the Windows OpenGL API, which would be fine except for the fact that Windows OpenGL is now at version 4.2 +.)
If your Mac PC has a better spec than your presumably older non-OS X PC, then I'd think this would be the ticket for you. Either way, you'll have to support two environments if you run Windows & OS X. Good luck!
Sorry didn't say but my windows machine is a "bootcamped" imac.
I'm not looking to install windows on my laptop as that's already dual boot linux and don't particularly want to partition it off more. Plus it seems like a lot of hassle for one game.
Thanks for the advice though, it's probably what I'll have to do, install it on the desktop.