I've got Kirby's Epic Yarn (God, I hate that name) at the moment. It is as sickeningly cute as you've probably heard, and even more so. It absolutely succeeds at the aesthetic it goes for; it looks beautiful, and the fabric textures help compensate for the Wii's lack of power. The little I played of Super Mario Galaxy, I thought it looked good enough, but it still suffered from the low resolution and whatnot. Kirby looks excellent, and you don't even need to qualify it with "...for a Wii game".
The whole presentation skews quite young. Probably a little too young for my tastes, and I'm one who'd usually slap someone with a fish for pulling "TEH KIDDIE" card. This includes the difficulty, at least as far as I've gotten. It seems to take the "no-fail" route; you can be harmed by enemies, or fall into pits, but it just scatters some of your beads about Sonic the Hedgehog-style, most of which you can re-gather, but I don't think you die if you take a hit with 0 beads. I know a lot of people didn't like this type of philosophy in, say, Prince of Persia (2008). I didn't mind it there--or in general, frankly--because I usually just want to enjoy and get through a game. Here, it seems a little out of place. I prefer the Super Mario World/Donkey Kong Country style of 2D platforming--fast, precise, with a bit of a challenge--and whenever I play something that deviates from that, I tend to not like it all that much.
That's not to say I don't like Kirby's Yarn. It has its appeal, but I don't think it'll keep me interested for super long. You can do a bit of decorating Kirby's Pad with the objects and furniture and patterns you collect in levels (also seemingly somewhat borrowed from LittleBigPlanet, along with some of the style), but it's fairly trivial stuff. I just do what it makes me do and get back to play the actual game, pretty much.
