It's decent? First of all, its not a wii exclusive, its on pc and psp too, I played the pc version.

It's kinda hard to describe, but you have a lot of control over the ball and the environment doesn't seems to affect the ball as much as in other games, which cheapens the challenge, however it makes up for it by going all out with the level design plus levels are quite long compared to other rolling ball games. The level themes are kinda cool, but the menus and overall presentation of the game feel extremely cheap.