It's surprising how overlooked it is (well maybe not since Nintendo hasn't hyped it at all) but Maboshi's Arcade is seriously cool. It's actually three very different games in one. At first they appear to be simple, but as you progress in them they turn out to be very difficult.
There's some other weird things happening in it. Up to three people can play at once, in side-by-side windows, and they can affect each other's games in weird little ways, even if they're playing different games. They're not competing against each other, instead it's more like accidentally nudging a pinball table, just little happenstance things. If someone's not playing in a given window then the computer plays, and its playing can affect your game in the same fashion.
Another strange feature... once in a while a special character, Mr. Maboshi, will show up in an empty window playing a special game unavailable to human players; the object is to use the cross-window effects to get his score up to 1,000,000. The score accumulates across plays, and things are unlocked each time the goal is reached.
But even without those extra gimmicks the games are interesting, especially "Square", which is diabolically clever.