Mario makes his RPG return in the sequel to the exception Paper Mario and the Thousand Year Door, on the Game Cube. Personally, I would rate The Thousand Year Door as one of the best console games I have ever played, so anticipation was extremley high for this game.
There are two major changes that are seen in Super Paper Mario. The first is the combat system. Previously, Mario and co would fight in turn based battles, taking it in turns until one either you, or the enemy was defeated. This has now been replaced with the traditional 2D platformer style combat system of either jumping on an enemy, or using a weapon against them. In some ways, this is a very good change, it certainly makes the game easier for newcomers to RPG's to get to grips with, it also makes the easier battles against enemies such as Goombas a lot less frustrating as you no longer have to go through the motions of enetering the battle just to wipe them with one blow, but, negatively, it does make many battles rather easy, especially against the end of level bosses and Count Blacks minions.
The next change is the way the game world works. No longer does it use the pop up book style worlds in The Thousand Year Door, but more of a flat colouring book style world. The game worlds aren't as fun to explore as they do feel a lot more restricted in where you go, but when using Mario, pressing the A button flips the world from 2D to 3D, revealing many hidden pathways and items that can be used. It does make for some more interesting puzzles as you will have to regularly flip between the 2nd and 3rd dimension in order to progress, but at the same time, it does make them a little on the easy side. They way you progress through worlds also seems a bit lacking. To go from one area to another, you have to go through doors. To me, this makes the each area feel detatched from the rest, usin pipes would make the world feel more complete.
Mario is no longer accomponied by a Goomba, Koopa Troopa, Bob-omb etc, but instead, Peach, Bowser and Luigi accompany him. You would think this would a good change, and in away it is, but for the most part, they all seem rather pointless. The truth is, that even though they all have their own special ability, these rarely ever come into use, so most of the time, you will find Mario much more useful. Mario is also accomponied by some srange creatures called Pixls. Like Peach and co, these all offer Mario abilities that help him progress throughout the game, and whilst they are without doubt, much more useful then the other characters, they lack the charm and just don't seem to be as imaginitive.
For the most part, the levels are pretty good. The Crags was possibly my favourite, whilst the third chapter was possibly the funnies. Sadly this can't be said for the Space level and Sammer land. The space level gets a bit annoying as you seem to do an awful lot of backtracking, whilst Sammerland is possible the most uneventful level in Mario history. You basically, fight a battle, walk through a door, fight another battle, walk through another door and so on. As I'm sure you can imagine, this soon gets tiresome.
For the most part, Super Paper Mario is a highly enjoyable game. It does have it's frustrations, but they don't usually get in the way of the enjoyment of the game. There is a lot of text, so if you don't like reading much, this game probably would be better left alone, but if this doesn't bother you, and you are a Mario fan, then there are a lot of gags in here that will make you chuckle. Hardcore RPG fans may also be put off as crossing the genre with 2D platformers makes it easier, and makes the game more accessible for everyone.