C2: Judgement Clay
Contributed by - Richard

Hyper speed:
Hold Y, and press L, L, R, Down, Left, R at the opening screen. The
speed may now be set to ten speed in the options screen. 

Random character:
Press R + L at the character selection screen. 

Secret characters:
Enter the following codes on the game selection screen: 

Peelgood
Hold Down/Left, then press B, Y, Y, A, Y. 
Sarge
Hold X, then press L, L, Up, Down, Left, Down. 
Jack
Hold Up, and press A, A, R, R, Y, A. 
Butch
Hold L and press X, R, A, X, R, R. 
Spike
Hold R, and press X, B, B, A, Y, Left, A. 
Ice
Hold B, and press Up, L, L, L Right. 
Thunder
Hold Up/Left, and press Y, B, X, B, B, X, A. 
Slyck
Hold Y, and press L, L, Up, L, Left, R. 

Activate all hidden characters:
Hold L + X, and press Up, Up, Select, Up, Up, Right.