I just finished this game with the minimal requirement of 70 stars, and so far, I have to say this much about the game, guys:
It is simply....A MASTERPIECE!
Seriously, everything about this game is so well-designed, it's almost impossible not to appreciate everything. The music is gorgeous, ranging from many new ones to a few re-used ones fron the first Galaxy, and even some remixes of old Mario games songs. The environments are stunningly beautiful, especially in the water worlds to my appeal, and gameplay-wise the game's just 100% fun to play.
Though that doesn't mean the game is easy. It's obviously no joke that Miyamoto said he wanted this game to be more difficult than the original, and boy howdy did they succeed at that by a long shot! The first few galaxy's may be easy for veteran Mario players, but especially in the later stages the hazards become SO incredibly tough, it surpasses Sunshine in terms of difficult platforming, but with enough practice in the stages, you'll be able to clear them just fine.
Anybody who loves platforming and wants a good game on the Wii now, don't hesitate, buy this now!