Neat concept, mediocre presentation.
The whole moving around a constantly rotating planet idea is cool and pretty original, and the graphics, although inconsistent (realistic planet, cartoony guy, etc) aren't too bad, but the whole game just isn't that much fun, and gets repetitive really fast. Put more in there. Bad guys, powerups, different levels, something that happens when you reach the end of the planet, like it wraps you around or knocks you off or something.