Very nice.
I think it was the gratuitous use of the word 'Extreme' (Xtreme) which won me over :)
Anyways, graphics: 7. They were nice to look at, bright and colourful. Really attractive, but quite simple in design.
Style: 8. The style of this was brilliant. The way the physics worked and how everything moved was, really, quite specatcular. My only gripe was that there wasn't much animation - you lost 2 marks for that.
The sound was near flawless. Great feel-good muzik (yes, muzik) in the background and appropriate sound effects wherever they were needed. They got a bit repetitive.
No violence.
Interactivity, that's always a hard one with games. You had a menu which was set out nicely and all that, but the actual content of the game was limited. All you do is press two keys (to my knowledge). For a game, that's quite a small ammount of control. However, the gameplay was nice and easy to pick-up, so you get a 6 here.
Not much humour, really - But it will definately make you smile.
Overall you get a very high 8/10. This game is really entertaining - I couldn't find much wrong with it at all and I really enjoyed playing it.
Excellent game, well done.