Half-Life Cheats

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.

Half-Life 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.

Half-Life 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.

Half-Life 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.

Half-Life 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.

Half-Life 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.

Half-Life Unlock Extras Menu
On the cheat entry menu, press TRIANGLE, SQUARE, LEFT, RIGHT, CIRCLE, X, UP, DOWN. If you have the Official Playstation Magazine Demo Disc #57, you can play the Uplink Mod by putting the CD into the system.