Supercross Circuit PS Cheats

Enter the following as codes in the Bonus Stuff menu:

ALLBIKES       All Bikes
MUTTON         Sheep Race
SLEEPYHOLLOW   Headless riders 
BIG_HELMETS    Big helmets 
FLOATING       Invisible bikes 

Thanks to Revolution readers cs1318, Hydrodude, Zach Batdorff, and Charlie West!