You posted the game on the Mac App Store with requirements of only OSX 10.6, I started up the game on my old laptop with an intel X3100 Graphics card (for no other reason that it what I was using at the time) it lagged on your companies logo screen, and the menu screen was nothing more than a black background with small grey plumes of smoke.
Ive got an Imac in the other room that will probably handle anything you can throw about it
, but you may want to update the system requirements on the mac app store and/or a release a demo so people wont feel gipped out of $10.