Wonderboy's okay. The graphics are cool, but it's a little like Sonic, though before it, in that it's a little fast-paced.
On running things, my old 1.8 P4 runs all the way up to Mame before the video re-write, Daphne, and many many tables in VP. Hell, I have the new beta Daphne running just fine on my PIII 733mhz. Daphne doesn't seem to take much. VP, though, especially the newer tables - say, 95 or so and up - to not jitter during mult-ball, your P4 may not handle those. What WILL help is if you have an AGP 8x, or even better a PCIe, card added.