Call of Duty 2: Big Red One

All Levels
Hold up on controller 2 at the level select and enter with start, select, select, square with controller one.

Invincisble
During gameplay hold R1+L1 and press Up, Up, Down, Down, Left, Left.

Never Die
Make a profile named Guzzo.

Unlimited Ammo
Make a pro named Dixon.

Unlock All Levels
Hold R1 & L1, then press Up, Up, Down, Down, Left, Left, Right, Right, Square, Right, Square, Right, Square.