At the main menu, select the Extras option. Then, choose the Enter Codes selection and enter one of the following codes. Choose the Activate Bonus Items selection under the Extras menu to activate the cheats.

Bonus vehicle in Diesel Dreaming level
Enter HOTROD as a code to unlock a bonus vehicle in the Diesel Dreaming level.

Bonus ship in Rocket Rodeo level
Enter SPACE as a code to unlock a bonus ship in the Rocket Rodeo level.

Play as Punk SpongeBob in Diesel Dreaming level
Enter SPONGE as a code to unlock Punk SpongeBob in the Diesel Dreaming level.

Play as Patrick Tux in Starfish To The Rescue level
Enter PATRICK as a code to unlock Patrick Tux in the Starfish To The Rescue level.

Play as SpongeBob Plankton in Super-Size Patty level
Enter PANTS as a code to unlock SpongeBob Plankton in the Super-Size Patty level.