Street Fighter: Ken Sei Mogura is, literally, Whac-a-Mole meets Street Fighter. Released only in Asia, players pound away at little M. Bisons that pop up through a series of holes. Successful hits determine a fight's outcome on the screen. Impossible to emulate on MAME, right?
Wrong. By sheer luck, someone discovered a vandalized Ken Sei Mogura cabinet in an abandoned location in the U.K., and eventually sent its printed circuit boards to David Haywood, a MAME developer in that country.
There's a load of technical detail about the ROM and how the cabinet was constructed at the link, but to make a long story short, Haywood found a way to emulate the mole popups on a ROM on PC. Essentially the player clicks a spot when it is lit to record a hit. Looks a lot easier than real-life Whac-a-Mole, whose critters always seem to be descending when the mallet lands.
"I hope you're now more aware of how MAME is always changing, always growing, and how things you might not have even considered emulation candidates very much are these days," Haywood writes. "If it can be emulated then as a project we're interested in emulating it."
Video of the entire game is above; skip to 1:37 to see the mole-whackin' in action.