Codes

  • Cheat menu cheats

    EffectCode
    Alien ModeUp, Triangle, Up, Triangle, Up, Triangle, Up and Triangle
    Infinite AmmoDown, X, Left, O, Down, X, Left, O
    InvincibilityLeft, Square, Up, Triangle, Right, Circle, Down, X
    InvisibilityLeft, Square, Right, Circle, Left, Square, Right, Circle
    Slow motionRight, Square, Up, Triangle, Right, Square, Up, Triangle
    Xen gravityUp, Triangle, Down, X, Up, Triangle, Down, X

    Contributed By: ElFreakoKid, floydfan, and agreatgamer.

Passwords

  • Unlock all Decay missions

    Go to the Options, then Cheats. To enter the code you must have two controllers.

    EffectPassword
    All Decay missions unlocked including bonus mission Xen Attacksp2_R3, p1_L3, p1_up, p1_up, p2_down, p2_down, p1_left, p1_right, p2_left, p2_right, p1_X, p1_O, START

    Contributed By: Hoaxer87.

Unlockables

  • Bonus Alien Mission

    Get an A-grade on all 9 of the Decay missions. If you successfully do this, you'll get to play a 10th level as a Vortigaunt alien. Getting an A-grade on this level will formally unlock the Alien Mode. (Note: the best way to ensure an A-grade for a level is to get at least 25 kills.)

    Contributed By: Cold NRG.

Secrets

  • Uplink Mod

    For this code to work, you will need a copy of Playstation Magazine Issue 57 (The one with Jango Fett on the cover) and it's demo disc. From the Half-Life main menu go to option and the the cheats menu. Enter the following cheat: Triangle, Square, Left, Right, Circle, X, Up, Down. It should open an extras menu on the options screen. Go to the extras menu and it should say opening disc tray. When it opens remove the Half-Life disc and put in the issue 57 disc and it should load the Half-Life Uplink Mod. Enjoy!

    Contributed By: Bahamut NEO ZERO.

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