Summary: Cool game, got it on a whim for my 6 year old and we really enjoy it. The tracks get pretty hard as you progress, but a game should challenge. The FMX tracks where you do bike tricks to achieve the medals stand out.
Summary: My friends and I play this all the time. I believe there's a free trial, so go play that instead of reading these reviews. The real game is about 2-2.5 times better than the demo, plus it has online multiplayer and custom user-made maps.