MAX Cheat Zone

Half-Life

Invincibility
Go to the Cheat Code screen in the Options menu and enter the following cheat to unlock Invincibility: LEFT, SQUARE, UP, TRIANGLE, RIGHT, CIRCLE, DOWN, X. Press START to confirm code. If done correctly, the code will appear in the box to the right. NOTE that this only applies to the character currently being controlled by Player 1 in a Single-player Decay game.

Unlimited Ammo
Go to the Cheat Code screen in the Options menu and enter the following cheat to unlock Unlimited Ammunition: DOWN, X, LEFT, CIRCLE, DOWN, X, LEFT, CIRCLE. Press START to confirm code. If done correctly, the code will appear in the box to the right.

Unlock Alien Mode
Go to the Cheat Code screen in the Options menu and enter the following cheat to unlock Alien Mode: UP, TRIANGLE, UP, TRIANGLE, UP, TRIANGLE, UP, TRIANGLE. Press START to confirm code. If done correctly, the code will appear in the box to the right.

Unlock Invisibility
Go to the Cheat Code screen in the Options menu and enter the following cheat to unlock Invisibility: LEFT, SQUARE, RIGHT, CIRCLE, LEFT, SQUARE, RIGHT, CIRCLE. Press START to confirm code. If done correctly, the code will appear in the box to the right.

Unlock Slow Motion Mode
Go to the Cheat Code screen in the Options menu and enter the following cheat to unlock Slow Motion Mode: RIGHT, SQUARE, UP, TRIANGLE, RIGHT, SQUARE, UP, TRIANGLE. Press START to confirm code. If done correctly, the code will appear in the box to the right.

Unlock Xen Gravity
Go to the Cheat Code screen in the Options menu and enter the following cheat to unlock Xen Gravity: UP, TRIANGLE, DOWN, X, UP, TRIANGLE, DOWN, X. Press START to confirm code. If done correctly, the code will appear in the box to the right.