Blue Hat:
Successfully complete the game to unlock a blue hat for Parappa. Press the Right Analog-stick at the "Press Start" screen to select the new color. Information in this section was contributed by belkin.

Pink Hat:
Successfully complete the game with the blue hat to unlock a pink hat for Parappa. Press the Right Analog-stick at the "Press Start" screen to select the new color. Information in this section was contributed by belkin.

Yellow Hat:
Successfully complete the game with the pink hat to unlock a yellow hat for Parappa. Press the Right Analog-stick at the "Press Start" screen to select the new color. Information in this section was contributed by belkin.

Song Test:
Successfully complete the game with the yellow hat to unlock a new dog house that allows you to listen to any song in levels that you finished with a cool rating. Information in this section was contributed by belkin.

Bonus Stage:
To unlock a bonus stage after any regular stage, finish the stage with a good score (near 1,000 points). You will be brought to Chop Chop Master Onion Head who gives you a fun, yet somewhat repetitious bonus game between the end of the stage you just finished and returning to the stage selection map.