The plot twists and turns, turns you upside down and completely entrances you along with gorgeous graphics.
The graphics are superb. Every effect in the book has been used to make the entire world paper (except for the pigs in Twilight Town for some reason) and Mario can make great use of his papery attributes. Mario can turn on his side to become near invisible, can fold himself into a paper plane or paper boat and even twist himself either way.
You can flick switches to make paper stairs peel off one wall and glue itself onto another, you can blow away walls with one of your partner's special abilities. The way you react with the game world is always fresh, exciting and surprising. You can even press switches that build paper bridges, but the way the appear looks like the turning pages of a book. The paper element is always funny, and Intelligent Systems have made sure that it is anything but a gimmick.
Another amusing thing is the constant references to Mario Sunshine. Isle Defino residents make constant appearences, and the amusing thing is that they are now the equivalent of the Mafia. You co-operate with the 'boss', Don Pianta on many occasions.
You can pay Shine Sprites to power up your partners and the water reminds you of Sunshine. It's good to see Nintendo making cross-overs to other first-party games, and these references are even better than the inclusion of Clairvoyant the Ghost in Luigi's Mansion, or the constant look-backs to Ocarina in Wind Waker.
The controls are top-notch. The A button out of combat lets you jump, the basic building block for special moves later in the game. You have a hammer, which you swing using the B Button. Like the original, you can jump on or hammer enemies to start a battle with an extra attack move. A simple, beginner friendly menu is activated by the Start button. Early in the game, you get the ability of turning sideways to slip through cracks in walls and the like. The aforementioned menu has lots of different sections, like the Crystal Stars you've collected, your map to the next star, your items (like Mushrooms which heal your HP, and Fire Flowers which damage your enemies during combat), and some more obscure things, like the renowned Toad Chef Zess. T's Recipe collection. The menu and controls are simply top notch.
Combat plays a major part in the game, but unlike most RPGs there are no random battles. You can see enemies coming towards you, and when they see you they run toward you to engage in battle. During battle you have a choice of Jumping, Hammering and using an item or star power on your enemies. You can also heal allies/partners during combat with Mushrooms and the like. The biggest difference about Paper Mario is the fact that the combat is being held in front on a stage in front of an audience. The audience is very amusing during combat. When you pull off stylish attacks or just powerful ones, they cheer and your star power rises. Attacks are chosen via a menu, then with sneaky little button presses, you really please the audience. Sometimes in battles you see a hazardous 'Press X Button Sign'. This means an audience member is about to throw an item at you, so you press X to vault down into the crowd and jump on or hammer the offender. This effect gives Paper Mario 2 a great comedy feel.
The story is told in individual chapters, and in each chapter you find a crystal star. Each is told in different town, so you see everything in the Paper Mario world. And the land is huge. Also each chapter is completely different to the last, for example the first has you taking the Crystal Star of a massive dragon named Hooktail, then the next has you leading an army of Punies around the Great Tree. Others include having your body stolen by an evil Ghost, catching a thief and traitor on a train in a stealth-ish way. The magic of Paper Mario is its Replay Value. I have finished the game, but I am currently playing it again, just to experience the full velocity of its charm and complete perfectness.
Paper Mario 2: The Thousand Year Door can be frustrating, but Nintendo have got on to a fantastic thing here. There are next to no flaws, except it's lack of difficulty until the end and its Play-Time (I wanted more than 20 Hours DAMMIT!!!). I take my hat off to you Nintendo, because you have created one of the most perfect pieces of game design ever. Everything about the game shines with an extravagant feel, but never selfishly so, and the world glowes with a unique and funny atmosphere. The charcters are lovable and hilarious, and this is a game that should be played by every Cube owner. Even if don't have a Gamecube, buy one for this game.
It is really that good.