Mario's second Paper Mario game is arguably not only an amazing game at a low price- but maybe the best game on the GC.
Before I get into the action, look at the price. 15$ for one of the best games on the GC? Oh yeah!
The story is that you get a letter for Princess Peach with a treasure map inside that shows you... treasure? And so you decide to go there and check it out to find that the Princess has been captured and you have to once again, save her. Along the way you get these Crystal Stars which these X-Naut badies want too to open the Thousand Year Door and you got to get them all before they do.
Anyway you start as none other then Mario (Like that wasn't obvious enough) and the entire game is in paper, which is unique. The style really starts to grow on you and before you know it, you want a lot of other games to look like this.
What really is a high point of the game is how the battles work. You start with Mario attacking, you're partner attacking, and then the enemie(s) attack which you need a lot of strategy. There is over 9 partners in this game but I won't go over them for spoiler reasons.
Because the game is made in paper in makes use of the 2D platforming goodness often. Also, because Mario is paper he can transform into other paper objects such as a paper airplane, become totally flat, and many more that make this game jammed full with lots of puzzles, and good puzzles at that.
This game has 8 worlds and each one takes about an hour and a half (Some more!) and that's just the main story. There is also lots of side quests, training, cooking, and lots of things so besides the main story so you'll have plenty to do.
As you go through every time you get a Crystal Star you get a new power to use which is very helpful, especially in the later fights where the enemies have lots of HP.
One of the best things of the Paper Mario series has always been the funny humor in this game. From breaking the fourth wall to even stupid things, it's very funny to watch.
Also inbetween chapters you get to do a little thing with Peach (You get to walk around and do things) and you also get to use Bowser who is always trying to catch up to Mario. Also, sometimes you go through a Super Mario Bros. style level which is fun and unique.
Music-Wise some areas aren't that big in music, but when music does come up it is very good.
This is a very excellent game at a cheap price, unique style, great music, unique battle system, great puzzles, great powers, over 10 hours of gameplay, (Only the main story in that) and it's very funny sence of humor obviously makes this game a buy. Buy it now.