Get All - Press back, then Up(2), Down(2), Left, Right, Left, Right, B, A [by: playa]
Full Health - Press back, then B, A, B, A, Up(2), Down, X [by: playa]
Full Ammunition - Press back, then B, A, X, Y, Left, Right, Left [by: playa]
Invincibility: During gameplay, press back to display the objectives window, then quickly press Down, Up, Down(2), Up, Right, Left, Right, Y, X(2), A. Your health will decrease but will never reach zero. [by: playa]