One complaint about the Wii that hasn't changed is that the number of quality games has not increased at a very fast pace. While the Wii library of games is growing, most new games are made by third parties, and those third party games tend to be poorly made, or at least poorly take advantage of the Wii's capabilities.
The upshot to this criticism is that when Nintendo makes a game for its own system, it does a bang-up job of it. With Super Mario Galaxy, they really hit the mark.
Of course, the plot really needs no introduction. Peach is kidnapped, save her from Bowser, blah blah blah. Okay, you don't play Mario games for their innovative stories. You play them because they're typically platformers of phenomenal quality.
Where do I start? I guess the control scheme deserves a mention. It's a bit difficult to get used to in the beginning; it's unusual to be controlling characters on a spherical surface, and the lack of camera control can be frustrating in rare occasions. However, after you get the feel for the controls? Man, does this game feel right. Smooth, accessible play that anybody could pick up and go with. The new features are integrated in nicely, too, like Bee Suit Mario and Boo Suit Mario. They're fun, though they do feel a little gimmicky.
Every level feels like it was crafted just right. The graphics are simply stunning, and the music evokes something while you're playing that you just don't get from most games. I really couldn't praise this game more.
There are two features I should mention, though. One is the two-player mode. Throughout the game, you can use the wii-mote to pick up "Star Bits" on the screen, and then fire them off at enemies. Since this can be a bit distracting while playing, a second player can take up a wii-mote and take over this function for the guy playing as Mario. While this seems like I nice feature, I can't help but think that it's not very fair to the second player. There just aren't enough enemies affected by the Star Bits to make it a very fruitful role, and otherwise all player two will do is wave the cursor around the screen trying to pick up Star Bits. Wee!
The other feature involves stat tracking. Each level keeps track of how many stars you've found and the highest number of coins and Star Bits you picked up in each level. You have the option of posting this information to an online message board, which other players can view, though I haven't looked at it yet myself. I wouldn't complain about this kind of feature, as it's one of the things that people seem to like about the XBox, but these things always leave me feeling so pressure. I don't play these games to unlock every last nook and cranny hidden feature, so the idea of having other people's scores as such staring me in the face does not strike me as being too appealing. Yes, you completed the game in a perfect manner. Good for you.
Those things aside, this game is bound to become a classic. If you own a Wii, there is no reason to not own it. It's fun to play, it's a joy to watch, and it's accessible to gamers of many levels without being too simple for more advanced players.