Well for the first time I find myself disagreeing about a Yahtzee review, weird that...
I thought that the whole gravity thing was the best part of the game, it gave a greater sense of freedom than a normal 3D platformer does and its fun to see if you can long jump right around a planet, and the camera was pretty much the best one any game has had in a long time, it never got stuck and was almost always in the best place to see the action.
I wouldn't disagree that a few bits of it felt a bit gimmicky but then again that describes a hell of a lot of games anyway (and I don't just mean Wii games). And yes, the boss fights were almost all terrible, especially the Bowser last ones.
Anyway, that's my irrelevant opinion cast out into the murky waters of the internet.