Level select:
Hold L and press Down, Up, Left(2), B, Right, Down, X at the main menu.

Unlimited health:
Pause game play, then hold L and press Y, X, Y, X, Y, B, Y, B.

Unlimited rage:
Pause game play, then hold L and press Left, Down, Left, Down, Right, Up, Right, Up.

All weapons:
Hold L and press X, B, Down, Left, B(2), Y at the main menu.

Unlimited ammunition:
Pause game play, then hold L and press Left, B, Right, X, Up, Y, Down, A.

Daywalker difficulty setting:
Hold L and press Left, B, Up, Down, X, B, A at the main menu.

Escorted NPCs are invincible:
Pause game play, then hold L and press X, B, Y, A, X, B, Y, A. This code can only be enabled in levels that you are escorting NPCs.