MiSFiT MAME
Did you ever play Pac-Man thinking "What if this had vector graphics like Asteroids?"  Or what if you combined Dig Dug and Mr. Do!, since people think they're so similar anyway?

Friends, your answer is here. In 1998, the program TURACO debuted, which lets you alter the sprite graphics in certain arcade games. Since then, a lot of very talented people have taken up the challenge of creating their own hacks. MiSFiTMAME is a version of MAME that plays a lot of different hacked versions of arcade games. You can also play a simulated version of Pong, Monaco GP (kind of), among others.

New Dig Do! Simpson's Tapper Vector Super Pac-Man Multipac 1.5