If you can make a NES controller mouse, and stuff a whole system into a shoe, then stuffing one into a game cartridge is clearly the next step (don't question my foolproof logic). And that's exactly what someone did (well, they actually put a Nintendo on a chip (NOAC) in there). As you can see it's got everything it needs to be a fully functional Nintendo. But the real question is this: If you try jamming this cartridge into another NES does it tear a gaping hole into the video game dimension and release retro gaming bosses to wreak havoc on our planet? My guess is yes. And I'm all for it if it means I stand a chance with Zelda. It's not that her doppelganger wasn't awesome in the sack or anything, it's just that one of her pointy ears came off while we were doing it. Talk about awkward.
nes system built into game cartridge [technabob]
Thanks to Andrew, who once stuffed a pinball machine into a grain of salt, for the tip