Thankfully, the first patch was sent out yesterday (amazed that something so obvious got past QA), so I was able to devote some quality time to the game. Currently, I'm at the start of Chapter 6. I'll give my overall thoughts once I've finished single player, but right now, the feeling is very good. I might even be inclined to put in a similar space as Mario Galaxy 2, in terms of it being a great refinement of the old elements and a deluge of new ones, and while it may be harder for it to create the awe and wonder of the original, you can see it's a better game quite clearly. Suffice to say, there have been several "Aha!" moments and one instance of "Oh, that's so cool" - yes, I said it out loud, and yes, I felt silly afterwards.
In the meantime, if any of you want to try out some co-operative puzzles, hit me up on Steam - RockyRoad15 - and we can sort something out. ;D