You can play all the Half-Life levels that Gordon Freeman went through as Adrion Shepard, but in the lab none of the scientists will talk to you.
Hidden audio
Approach the Boss of Opposing Force to hear backwards audio composed of the phrase "To win the game you must kill me Randy Pitchford" when played correctly. Randy Pitchford is the leader of the development team at Gearbox Software.
Cheat Codes
Load the game with the "hl.exe -dev -console -game gearbox" command line. Then while playing the game, press ~ to display the console and enter one of the following codes to activate the corresponding cheat function:
Weapon names
Use one of the following weapon names with the "/give weapon_[weapon name]" code:
WeaponWeapon name
.357 Magnum357
9mm Assault Rifle9mmar
9mm Handgun9mmhandgun
Crossbowcrossbow
Crowbarcrowbar
Desert Eagleeagle
Displacerdisplacer
Egon Gunegon
Gauss Gungauss
Grapplegrapple
Hand Granatehandgrenade
Hornet Gunhornetgun
Knifeknife
Laser Tripminetripmine
M249 SAWm249
M40A Sniper Riflesniperrifle
Pipewrenchpipewrench
Rocket Throwerrpg
Satchel Chargesatchel
Shock Rifleshockrifle
Shotgunshotgun
Snarksnark
Spore Launchersporelauncher
Ammo names
Use one of the following ammo names with the "/give ammo_[ammo name]" code:
Ammo typeAmmo name
.357 Magnum357
9mm Assault Rifle9mm
9mm Handgun9mm
Crossbowcrossbow
Egon Gunegonclip
Gauss Gungaussclip
M249 SAW556
M40A Sniper Rifle762
Rocket Throwerrpgclip
Shotgunbuckshot
Spore Launcherspore
Map names
Use the following map names with the "/map [map name]" code: