Motocross Fever is a pretty advanced game for an online flash game.
It's more something that you would expect to see on a PSP or Gameboy/Nintendo DS.
In this game you drive a motorcycle in various motocross events. The graphics are pretty good and the gameplay is pretty simple, but fun.
You can't crash or fall off your bike (is that good or bad?) but it does get challenging as you pass to the more advanced levels.
Play the game