Half-Life
  
Playstation


  


Invincibility:


  In the Cheat menu type Left, Square, Up, Triangle, Right, Circle, Down, X.


  


  Invisibility:


  In the cheat menu type Left, Square, Right, Circle, Left, Square, Right, Circle.
Slow-Motion:


  In the cheat menu type Right, Square, Up, Triangle, Right, Square, Up, Triangle 
  


  


  Unlimited Ammunition:


  While in the game type Down, X, Left, Circle, Down, X, Left, Circle. 
Infinite Ammo:


  While in the game press pause and type Down, X, Left, O, Down, X, Left, O. 
Xen Gravity:


  While in the game press pause and type Up, Triangle, Down, X, Up, Triangle, 
  Down, X.
Alien Mode:


  While in the game press pause and type Up, Triangle, Up, Triangle, Up, Triangle, 
  Up, Triangle.




  Thanks to Revolution reader MudDustKnot!