You didn't ask, per se, but most people are wondering the same thing, can you run PC games....
Short answer is 'NO', even the fastest Mac, running a very mature highly optimized accelerator like Virtual PC, cannot run the latest PC 3D games......2D games, if they are spec'd low enough will work, but if it required hardware 3d acceleration, in general, you can forget about it....no modern 3d games will work at playable speeds.
Thats on a Mac, and on the Amiga, the situation is even worse, with less optimized emulators, and even less likely someone would right the native 3d driver to emulated machine drive interface that you would need to get 3d acceleration working in the emulated box.
And on the amiga where the native 3d stuff is likely only a subset, not a superset of what the emulated machines 3d driver...well, a lot has to change before getting 3d accelerated games (even of the Mac variety) to work on Amiga hardware.