All Weapons
Pause the game, hold L and press Right, X, X, Y, X and release L. Got HMB will appear on screen. Now more weapons will be added to your firepower depending on the level.

Slow Motion Mode
Press Pause, hold L and on the control pad press Left, Down, Up, Right, and X and release the L button
Fish Eye Camera
Press Start to pause game play, then hold L and press Left, Up, Right, Down, X. A message will confirm correct code entry. Repeat the code to disable its effect.

Invisible Mode
Press Start to pause game play, then hold L and press Up, Left, Right, Up, X. A message will confirm correct code entry. Repeat the code to disable its effect.

Level 2: Easy Completion
When the spotters see you, they will call in an air strike. After you kill the first spotter, hide under the bridge.

Alternate Fade
Press Start to pause game play, then hold L and press Right, Up(2), Down, X. A message will confirm correct code entry. Repeat the code to disable its effect.

Alternate lighting
Press Start to pause game play, then hold L and press Up, Right, Up, Down, X. A message will confirm correct code entry.

Beagle holes, footprints, and burns
Press Start to pause game play, then hold L and press Down, Up, X, Y, X. A message will confirm correct code entry