Super Paper Mario Cheats

Unlockables

Item and Stages
Extra Mini Game in the Flipside's Basement - Get the Golden Card
Flipside's Pit of 100 Trials - Beat Chapter 1 and unlock the outskirt in Flipside
Flopside's Pit of 100 Trials - Beat Flipside's Pit of 100 Trials

New Pixls
There are 4 other Pixls you don't need to beat the game, but they help.
Barry(Provides force field) - Beat Francis in Chapter 3-4, then find Barry behind a bush in Chapter 3-1
Dashell(Speed boost) - The bottom of Flipside Pit of 100 Trials.
Piccolo(can trigger in-game events and cures status) - Place the 6th pure heart, talk to Merlee and help her, talk to Merluvlee, then Bestovious, Watchitt, Merlumina, then Merluvlee to get Random House Key.
Tiptron(like Tippi) - Buy it from Francis after you beat the game for 999 coins.

Secrets
Game Arcade
If you go into 3-D mode while in the coffee shop in Flipside B1, you can access a gold pipe that will take you to an arcade where you can play three different arcade games using different functions of the Wii remote, winning prizes for top scores. A fourth game can be unlocked if you have a Gold Card (obtained in the Flopside Milk Bar by going 3-D and opening a treasure chest).

Infinite Experience Easily
Need to get a level up, but keep dying in the Pit of 100 Trials? Then if you've beaten Chapter 5 (The one with the Crags and the Sapiens) go back to 5-4. Remember that pipe that just kept on sending out annoying Sapiens? Just jump on the block right next to it, then use Bowser's flame, and he just keeps killing the Sapiens, because they just keep coming out, that's 500 experience every 3 or 4 seconds and 10,000 or 7,500 every minute! (NOTE: This has been corrected in the PAL version).

Infinite 3D with Mario
Beat Flopside Pit of 100 Trails twice and get Mario's Card. This will allow you to go in 3D for as long as you want.


source: gamefaqs.com

see Super Paper Mario

see also other Wii Game Cheats:
Metroid Corruption Cheats
Resident Evil 4 Wii Ed Cheats
Mario Strikers Charged Cheats