I'm not sure at what point it becomes truly fair to write a "final" verdict on Super Mario Galaxy 2. After beating the game, you've still got a whole 'nother world to play through, and even after collecting "all" 120 stars, you're tasked with collecting... *gulp*... another 120!
 
For full disclosure's sake: I just passed that second milestone, beating the game's final level for a second time only to learn that a whopping 50% of the game's stars still elude me. So, for my sanity's sake, let's consider that latter 50% purely "game-plus" material, and let's forge ahead with my verdict on SMG2!
 
The Good: Graphics, level design, and controls are all great, as I mentioned before. The sound design is fantastic. And the many worlds of SMG2 are all so unique that the game as a whole never stops demanding to be revisited. But what else could you expect? It's Mario! It's platforming at its finest!
 
The Bad: Half of the "cosmic clone" stars and half of the "purple coin" stars had me pulling my hair out, and the "fluzzard" levels (which rely entirely on motion controls) were annoying. Also, I don't understand why every time I'd reset my Wii, the game would reset my total lives to four, no matter how many more I'd managed to accumulate. But these are minor complaints.
 
The Stand-out  Moment: Reuniting with Yoshi for the first time.
 
The Verdict: 9.5 (out of 10)

I'm not sure at what point it becomes truly fair to write a "final" verdict on Super Mario Galaxy 2. After beating the game, you've still got a whole 'nother world to play through, and even after collecting "all" 120 stars, you're tasked with collecting... *gulp*... another 120!
 
For full disclosure's sake: I just passed that second milestone, beating the game's final level for a second time only to learn that a whopping 50% of the game's stars still elude me. So, for my sanity's sake, let's consider that latter 50% purely "game-plus" material, and let's forge ahead with my verdict on SMG2!
 
The Good: Graphics, level design, and controls are all great, as I mentioned before. The sound design is fantastic. And the many worlds of SMG2 are all so unique that the game as a whole never stops demanding to be revisited. But what else could you expect? It's Mario! It's platforming at its finest!
 
The Bad: Half of the "cosmic clone" stars and half of the "purple coin" stars had me pulling my hair out, and the "fluzzard" levels (which rely entirely on motion controls) were annoying. Also, I don't understand why every time I'd reset my Wii, the game would reset my total lives to four, no matter how many more I'd managed to accumulate. But these are minor complaints.
 
The Stand-out  Moment: Reuniting with Yoshi for the first time.
 
The Verdict: 9.5 (out of 10)

Super Mario Galaxy 1 also does the "number of lives" reset.  I once had 34 lives stocked up, only to return a few hours later to three or four lives.  Not that I've needed a continue yet so it's not a real complaint, just strange.  Glad you enjoyed it!  Did you use your $20 credit at Amazon yet?

I found the purple coin challenges just as easy as they were in part 1. Except for the one in that... Wood clock stage thing, forgot what it was called. Only one that got annoying. Didn't entirely mind my lives resetting, since I mainly used 3 or so in the really difficult stages.
Collecting the green stars is already boring, and I only grabbed 8 of them. Ah well. I'll probably finish up in a month or so, since I only really grab 4 stars each day. Unless I feel like going to a nice 10-20 stars.

Green Star Challenge is mainly me thinking "Could they have put it on this insane spot?" and then jump off the ledge only to die. So it's hardly that exciting since most of the time they're in plain sight before you reach them. Then again I decided to grab the ones in Boss Blitz first, and well... You see one of them during the load screen. Yeah. 
 
I still only have 8 stars in it, and I'm currently too lazy to grab the rest.