Activate the following cheats by entering the corresponding codes while the game is paused. Note: there is a five minute lockout before a code can be re-enabled:

CHEAT FUNCTION - CHEAT CODE
$1,000 - Pause game play, then press SQUARE, CIRCLE, SQUARE(2), CIRCLE, L.
Full ammunition - Pause game play, then press CIRCLE, Left, CIRCLE, RIGHT, SQUARE, R.
Full health - Pause game play, then press Left, SQUARE, RIGHT, CIRCLE, RIGHT, L.
All cinematics - Pause game play, then press CIRCLE, SQUARE, CIRCLE, SQUARE, SQUARE, L.
Skip intermission sequences - Hold L + R and tap START(2).