I have a PS/2, and only a few games for it. Most are variations on the Dynasty Warriors franchise, because they're simple and fun. The combos are pretty easy, as everyone uses the same button pushes, it's just that they do different things. And there's nothing quite so stress-relieving as hacking through swarms of enemy soldiers with your halberd, occasionally impaling one and flinging him around into his compatriots.
The other games I've gotten for it I haven't finished. The 3-D Castlevania was so annoying it wasn't funny. I hate games like that and Devil May Cry where the camera angle is pre-determined, so, say, YOU CAN'T SEE WHERE THE (BLEEP BLEEP BLEEP) YOU'RE SUPPOSED TO JUMP TO! Sorry, I'm still miffed at that.
I don't have any FPS games, but I really wasn't that good at those in the first place.
Brad