One-hit kills:To activate one-hit kills, pause the game in Single-Player mode. Then, while holding RB, click Left Analog-stick, Right Analog-stick, Left Analog-stick, Right Analog-stick, press A, B, click Left Analog-stick, Right Analog-stick, Left Analog-stick, Right Analog-stick, press X, Y.TAR-21 assault rifle:To unlock the TAR-21 assault rifle, go to the “Press Start” screen. While holding RB, press Down(2), Up(2), X, B, X, B, Y, Up(2), Y.GI John Doe mode:To activate GI John Doe mode, first pause the game. Then, while holding RB, click Left Analog-stick(2), press A, click Right Analog-stick(2), press B, click Left Analog-stick(2), press X, click Right Analog-stick(2), press Y. If entered correctly, the message “GI John Doe Mode” will appear. In this mode, guns fire blue and red lasers.Third Person view:To activate Third Person view, first pause the game. Then, while holding RB, press X, B, X, B, click Left Analog-stick(2), press Y, A, Y, A, click Right Analog-stick(2).Super Ragdoll mode:To activate Super Ragdoll mode, first pause the game. Then while holding RB, press A(2), B(2), X(2), Y(2), A, B, X, Y.M468 rifle:To unlock the M468 rifle, go to the “Press Start” screen. While holding RB, press Up, Y, Down, A, Left, X, Right, B, Left(2), Right, X.Big Head mode:To activate Big Head mode, first pause the game. Then, while holding RB, press B, X, A, Y, click Left Analog-stick, press Y, A, X, B, click Right Analog-stick.Comcast Event multi-player map:To unlock the Comcast Event multi-player map, go to “Extras”