I don't think Pong actually works in MAME, last I heard...and it's a 2-player only game, so you're safe!
OK, I just researched a bunch of games & tested them quickly & took some notes. I'll post the next contest later today.
Thanks,
-Jason
Pong is built into a very early version of mame, which I have somewhere. Hard to see how that was relevant to the mame mission, but its nice to have it handy...