Best Ending
Get a COOL rating (finish the level with a cool rating) on every level and you get a new level were you watch Sunny Funny and Katy Kat dance on a table. You can change the view with the D-pad, zoom in and out with R1 and L1, and change Sunny's and Katy's clothes with the X and Triangle buttons.

Easy Fleaswallow Mode
In the third level, ignore the beat given to you at the top. Instead, follow Fleaswallow's beat to the button given at the top of the screen (while holding left). If done correctly, Parrapa will only the utter the first syllable of each sentence while alternating between Good and Cool. This is a funny and easy way to get past Fleaswallow's stage.

Hidden Images
In Level 1, hold Up and keep rapping. After awhile the background should open for a second and reveal a picture of a crazy onion head in the shower. (No, he's not naked.) This works on other levels as well.

Rap on your own
If you get a "cool" rating on the last level you get to rap on your self by just pushing the buttons. If you rap for a long time you will get over 3000 points, be able to watch the Karate guy break dance, and beat the level.