Infinite Swags
While playing, hold L1 then press Up, Up, X. You may have to pause the game before entering this code. Can someone confirm this?
Invincibility
While playing, pause the game and press Circle, Square, X, Square, Circle, Square, Circle, Square, Triangle, Square, Circle, Triangle, Circle, Square, Triangle, Square. That "Paused" word should turn red.
Level Select
At the title screen, press Square, Square, Down, Down.