Infinite Ammo
     At  the main menu, hold L1 and press Left, Circle, Right, Square,
Up, Triangle, Down, X.

Infinite Health
     At  the  main menu, hold L1 and press Triangle, Square, Triangle,
Square, Triangle, Circle, Triangle, Circle.

Infinite Rage
     At  the  main  menu,  hold  L1  and press Left, Down, Left, Down,
Right, Up, Right, Up.

Invincible NPCs
     Make  the  players  you're  taking  care  of on the escort levels
invincible  by  going  to  the  main menu, and while holding L1, press
Down, Up, Left, Left, Circle, Right, Down, Square.

Unlock All Missions
     At the main menu, hold L1 and press Down, Up, Left, Left, Circle,
Right, Down, Square.

Unlock All Weapons
     At  the  main menu, hold L1 and press Square, Circle, Down, Left,
Circle, Circle, Triangle.

Unlock Daywalker Difficulty
     At  the  main  menu,  then  press  and  hold L1. Then press Left,
Circle, Up, Down, Square, Circle, X.