Hello and welcome.
Unfortunately, it is a PowerPC application, which isn't supported in Mac OS X Lion 10.7.5. You could however run it under Windows via Boot Camp, Parallels, or Fusion. That would require the purchase of a copy of Windows XP and Parallels or Fusion if you went that way. Total cost would be $100-200. It would also require a bit of setup. Not sure if that would be worth it just for one older game.
C