Beat the game then return to the level selection screen.
3/3/2005
Bonus Free-style Level
Similar to the original Parappa, when you beat all the levels (Lammy, Parappa, 2 player Cooperative, and Competition) successfully, you unlock a new feature in the main menu called "Special" which is a series of special bonus stages that allows you to jam out with all the characters featured in the in-game play with all the songs and different variations ("Cool", "Good", "Bad", ect).You do NOT have to get a "Cool" on every level to unlock it. Only beat the game successfully, like with a "Good" rating or earn more points than your opponent. You know you beat a level when it doesn't look like a Chocolate bar anymore.
Complete ALL Single and Two Player levels successfully
5/9/2007
Sound Test
On the stage select menu, if you uncover all the peices of chocolate, you will be given a new option called Special. When you select special it will take you to a sound test menu. You can listen to every song from the game and press L1 or R1 to see each character perform a special move.