You can unlock additional characters and outfits by entering the codes below 
on the main menu. 

DOWN, DOWN, UP, RIGHT, LEFT, DOWN, SELECT, START - Tapout Crew, including 
Punkass, Charles "Mask" Lewis and Skyskraper 
LB, RB, RT, LT, LT, RT, RB, LB, Y, X, X, Y, START - Unlock BJ Penn's Black Trunks