Downhill Domination is... honestly stupid as all hell, but by design: it's a lot of fun :P
It's a downhill mountain bike racing game with a combat system, and it's ridiculous. You start being able to punch the bicyclists next to you; once you knock enough of them off their bikes you upgrade to being able to kick; then iirc you eventually get a stick or something lol. Otherwise, it's just another get-from-point-A-to-B-as-fast-as-possible game that doesn't require a lot of thought.