Unlock All Levels:
Play the game until you have passed the first subway level. Once the next level has loaded, go to the main menu and press... UP, DOWN, LEFT, RIGHT, UP, LEFT, DOWN, CIRCLE. Go to the load menu and all levels should be unlocked. When you start each of the levels you will have the same inventory that you had when you completed the first subway level.
Press start during gameplay and enter L1, L1, L2, L2, R1, R1, R2, R2.
All Weapons and Full Ammunition:
Pause the game and press L1, L2, R1, R2, Triangle, Circle, X, Square.
Slow Motion Sounds (toggle):
Pause the game and press L1, L2, R1, R2, T, Square, X, Circle.
Unlimited Bullet Time (toggle):
Pause the game and press L1, L2, R1, R2, Triangle, X, X, Triangle.
8 Pain Killer Pills:
Press Start to pause game and press L1, L2, R2, R1, Triangle, Circle, X, Square.
Part 2 Chapter 2 On the first crane you come to, the cab door is open. Jump from the top of the door to the top of the cab. Then carefully jump onto the crane arm and walk up it to about the mid point. There are some large crates to the left of the arm. Align your sight with the left side of the crates and, after brandishing a gun, shootdodge forward. Max should land safely on the concrete ledge. On the left end is a room with grenades and some ammo. Be sure to utilize the crate along the ledge when jumping down.
Thanks to Revolution readers Klump, beefy and Keith Maguire!