Shake it, ladies:

Get a COOL, {finish the level with a cool rating}, on every level and you get a new level where 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 and Katy’s' clothes with the X and Triangle buttons.

Stop A Head:

While playing the game look at the top of the screen where it tells you what buttons to push, you'll see 2 heads go across the screen. The first is the trainer's and the second is Parappa's. When Parappa's head is on the button marking, that is when you hit that button.