Quarth, or block hole in some places is an extremely fun action puzzle game where the object is to make even shapes of fallling blocks. How? By shooing squares...yes, a shooter puzzle game.
It's on game oldies right now, quarth is the gameboy version and block hole is the arcade version. You can play the gameboy color version on this collection: http://game-oldies.com/play-online/konami-gb-collection-vol-2-nintendo-g... Select the one titled "block game'.