Super Mario Galaxy 2

I loved... or am loving, I should say, SMG1. I'm at 82 stars and it's still unique and interesting. So I've been thinking about picking up SMG2 but I want to know more about it before I do. I hear there's 240 stars instead of 120? Does it stay fresh that entire time? Is it just because there's twice as many levels? What else is different from SMG?

Tell me about it.

Also, don't link to the Yahtzee video. Already seen it. Looking for personal posts.