Like mini-golf you're rewarded for sinking the marble into the goal with as few shots as possible. Score enough birdies and eagles under par and you'll unlock more courses to play -- and there are quite a few in total.
Crazy Golf ends up being pretty challenging and replayable, and you can pass the DSi around or link up wirelessly with up to three other systems to tackle the courses in multiplayer mode. Not a bad design at all. Just a really bad name.