Bargain price!
The frame rate is a little dodgy. It doesn't really track progress or give you proper updates at where you are in the game, nor does it tell you when you've actually completed the game.
Apart from that - which will hopefully come in later updates I found it an ok game. It passes time. Graphics do look good. Takes a bit of getting use to. It's fun kicking other riders off their bikes.
Also try the Peru level (the one in the clouds). It took me a week to complete that one! I've also yet to complete the last level - you have to be on the tracks the entire time at full speed to finish.