Cheat List:
You must first Finish all mission objectives in the single player game before the cheats become available. Then, during gameplay, press BACK, then press the following buttons to activate the corresponding cheat:
Big Heads: A,X,B,Y,A
Big Bodies: B,B,Y,X,X,A
Chicken Explosives: X,X,Y,A,B
Paper Mode: B,A,X,Y,A
Slow Mo: Y,Y,B,X,A
High Pitched Voices:X,A,Y,B,X
Unlock Characters:
W. Jacobs – Finish Special Objective in Campaign Mission 1 on any difficulty
H. Ramirez – Finish Special Objective in Campaign Mission 2 on any difficulty
K. Henkel – Finish Special Objective in Campaign Mission 3 on any difficulty
J. Stone – Finish Special Objective in Campaign Mission 4 on any difficulty
S. Grey – Finish Special Objective in Campaign Mission 5 on any difficulty
B. Gordon – Finish Special Objective in Campaign Mission 6 on any difficulty
A. Galinsky – Finish Special Objective in Campaign Mission 1 on Recruit during a Quick Mission in Mission Mode
D. Munz – Finish Special Objective in Campaign Mission 2 on Veteran during a Quick Mission in Mission Mode
N. Tunny – Finish Special Objective in Campaign Mission 3 on Elite during a Quick Mission in Mission Mode
L. Cohen – Finish Special Objective in Campaign Mission 4 on Recruit during a Quick Mission in Mission Mode
G. Osadze – Finish Special Objective in Campaign Mission 5 on Veteran during a Quick Mission in Mission Mode
S. Ibrahim – Finish Special Objective in Campaign Mission 6 on Elite during a Quick Mission in Mission Mode