A friend has a 60-in-1. For some reason in Centipede when you kill a spider, the score is backwards. it says 003 instead of 300, 006 instead of 600 etc....
I would just throw a PC in there. That way you can run whatever the hell game you want including Dragons Lair, Space Ace and even the AAE emulator for the vectors. After all, all the X-in-1 boards are just Mame on a stick anyhow....