Despite the massive amount of overhype it's endured, Galaxy is an amazing game, and the best Mario in a long time.
Story: Mario? Story? This is blasphemy! Mario's gotta save the princess! That's all there is to it! Or at least, that's all there really ever was there to it. We never expected any more from Mario; maybe a few extra twists, but as long as we have Mario, the Princess, Bowser, and hopefully Luigi or Yoshi, we've got ourselves a Mario game. Galaxy doesn't skew too off from this formula, yet has a fairly enjoyable story. Basically, Bowser captures the princess (o rly?), but this time, instead of just kooping (lol pun) her in a castle and sitting around, waiting for Mario to show up, he's creating a galaxy from which he may rule the universe. Now ruling the universe...you can't get much bigger than that. Along the way to help you is Rosalina, a woman who, despite looking similar to Peach, doesn't want to get it on with Mario. She lives on an observatory (Brawl stage, anyone?) with all of the little Lumas (who look like fat pudgy power stars). Speaking of power stars, they actually have a purpose in this game (gasp!). You see, they power up the observatory, which is really a giant ship, so that you may go save Peach. A bit more impressive than New Super Mario Bros., to say the least (in which you're walking along and Bowser Jr. randomly nabs the Princess).
Control: If you've played 64 or Sunshine, then you'll be well at home. All of the little tricks such as backflips and triple jumps and super jumps have been left in, so if it weren't for the enhanced graphics and the beautiful soundtrack, you'd think you were playing an older game. But that's not to say that the controls are exactly the same as before. For instance, you can point at the screen and shoot starbits (the coins of this game, as they appear pretty much everywhere) with B. You can also shake the remote to spin, which is used very often. It has some restraint, though there are points where it's just plain stupid (such as shaking the remote to shoot fire). But I digress; the controls, though reminescent of the smooth controls of the N64 and Gamecube, feel very refreshed and new while not screwing too much up.
Graphics: I hate to dis my more preferable series such as Fire Emblem and Zelda...even Brawl might be beat by Galaxy's graphics. Some might argue that Brawl looks better, but the difference is that, while Brawl looks more realistic (Brawl? Realistic? WTF?), Galaxy has a very bright charm to it, as each of the character shine radiantly. It's kinda like playing a very awesome cartoon; childish yet advanced. Graphics are good. Next subject...
Audio: I'll get to the music in a sec, since I'll spend much more time on it. There are a select few voice clips in Galaxy (mostly Rosalina and Peach, and a little Luigi), but mostly "YAHOO!"s and whatnot. We don't want Bowser or Mario talking. Ever. Same goes for most Nintendo characters. This game gives us a warning as to what will happen if they start giving Link and Mario their own lines. How? Just hit the disc channel with Mario in it, and you'll know what I mean. "SUPAH MARIO GALAXEEEEE!!!". Yeah, stick to the "It's-a me, Mario", Mario. Now that I've gotten that out of the way, let's move on to the music, shall we? Now I enjoy games for how epic they are, and...well, let's face it, with their overly cheery and MIDI-filled soundtracks, 64 and Sunshine were lacking on the epic side. Galaxy is a completely different story; that first level alone is beautiful enough to make you almost cry for joy. The soundtrack has pretty much two sides: there's the epic side, which you'll find on most of the worlds and on the observatory, and the nostalgic side, which you'll find on mini game worlds (Mario 3/World music), and Bowser music from 64. The soundtrack strikes a perfect balance of nostalgically old and awesomely new. Other than a select few games (namely Fire Emblem and Kingdom Hearts), I'm not sure if there's ever been a soundtrack as amazing as this.
Length: ...damn. If anyone's played 64 or Sunshine, then you know what I'm talking about. So many power stars...120 in this game (technically 121). Each one is its own difficult mission, which means that this is a hell of a long game. The main quest can end at 60 if you so choose, as that's all you need to go fight Bowser. But just think about it; at the end of the entire game, you're really only halfway through. That means that this game could bridge on into 30, 40, maybe even 50 hours. The good thing about this game is that it CAN be long, but it doesn't HAVE to be long.
Replay Value: The cool thing about the game is that you can replay all of the missions as many times as you want, even the Bowser fights and whatnot. Each mission is relatively short, so on a mission to mission basis, you could play it over and over. However, as a whole, there really is no reason to start ALL over again. I mean, it's just stupid. Play the missions again, fewls, not the whole game.
Multiplayer: There is a wee bit of multiplayer here, albait very limited. A second player can point at the screen and shoot starbits, and they can also increase the jump height of Mario to some extent. Your friend would have to be pretty damn patient, but multiplayer is indeed possible.
Boss Fights: Just like pretty much any Mario game, the boss fights here are challenging, but not to the point where you wanna smash the TV (well, to be fair, there are a few of those as well). They are all unique, creative, and fun. There's a giant flaming octopus, a fish made of bones, and not to mention all of the Bowser/Bowser Jr. fights. Which brings us now to...
Final Boss: Bowser is the eternal video game villian. Despite being in a more childish game like Mario, Bowser is still one of the most recognizably badass villians of video game fame. The Bowser fights in this game, although by no means identical, are similar enough to the ones from 64 so that you feel like you're at home when fighting him. The final fight with Bowser has an incredible music score, and in general...it's amazing.
Extras: I probably should've mentioned this back at controls, but I think I'll do so now. There are lots and lots of different suits. There's the Bumblebee suit, Boo suit, Fire suit, Ice suit, and many more. Although some can get annoying (bee suit cough), they are all entertaining, and a nice flashback to the days of Mario 3, when we could fly as a racoon or hop around in a giant boot.
Final Statement: Like I said before, I do NOT like Mario games. In my eyes, every Mario game past Yoshi's Island has just been Nintendo milking the series for all it's worth. The games weren't bad; they were just no where near as good. But then came Galaxy; Galaxy literally blew me away in a way that I could never imagine Mario doing. If you're a Mario fan, then please, PLEASE, get this game. If you're not a Mario fan, then you should become one. If you are a Wii owner, then you should own three games: FE10, Brawl, and this.