Blue hat
Finish the game to unlock a blue hat for Parappa.

Pink hat
Finish the game with the blue hat to unlock a pink hat for Parappa.

Yellow hat
Finish the game with the pink hat to unlock a yellow hat for Parappa.

Song test
Finish 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.

Ninja Star Mode
At the stage selection screen, hold R1 + R2 and select a stage to play the current level in ninja star mode. In ninja star mode, the button icons are replaced with ninja stars, which are wild cards.

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.

Secret song
Go though the opening FMV sequence to the part where PaRappa is writing his name and all the characters appear. Wait until a demo of the game appears. Go though the demo and the opening FMV sequence will appear again. Go though that and go though the part where PaRappa writes his name and wait again. Instead instead of them showing a demo, the colorful noodles will appear on the sides of the screen and the song will start playing.

Sunny's music video
Successfully complete the game with the yellow hat, then do the "Secret song" trick. Go though the whole song, then a music video with Sunny singing her intro music on stage will begin.

Control time of day
The game places Parappa's neightborhood at the same time of day indicated by the PlayStation2's time setting. For example, if you set the Playstation2's time to 11:30 a.m., it will be bright and sunny in the game. If it is 7:00 p.m., it would be sunset. If you set the time to 10:30 p.m. it will be dark outside.

Skip Opening Stage Cinematics
At the Stage Selection screen, hold L1 + L2 and then select a stage.