Expendable Cheats...
Extra Credits
Press a, b, left, a, b, right, b, a, down, right trigger on the pause screen.
Extra Lives
Press a, b, x, y, left trigger, right trigger, up, down, left, right on the pause screen.
First person view
Pause the game and press L, Left, R, Right, X(2), Down(2), R, L.
God mode
Pause the game and press Up, Down, Left, Right, L, R, Left, Right, Start.
Grenades
Pause the game and press Down(5), Up(4), R.
Instant victory
Pause the game and press L, R, L, R, Left, Right, Left, Right, Y, X.
Level select
Pause the game and press Up, Down, Up, Down, Up, Down, Left, Right(2), Y.
Level Skip
Press y, y, x, x, left trigger, right trigger, down, down, up, up on the pause screen.
Shields
Pause the game and press Up, Down, Left, Right, X, Up, Down, Left, Right, Y.