Porting a game from Windows to Mac is hard, because of all the restrictions of the Mac.
Most developers don't even bother with it, so be glad there actually is one.
If you want to be a gamer, then you should consider ditching the Mac. It's just not for you.
Half Life was originally designed for Windows. That's fine on Mac.
Age of Empires was originally designed for Windows. That's fine on Mac.
Halo was originally designed for Windows. That;s fine on Mac.
There are a lot of games that were ORIGINALLY designed for Windows. But they work fine with Macs.
They have more than a dozen programmers for their games. Badspot works alone.