Cheat Codes
Console Cheats
The Developer's Console must be activated first in the Options/Keyboard Tab/Advanced Button. In the new window, check Enable Developer's Console and click OK/Apply. Now, in the Main menu or while in-game, press ~(Tilde) to bring up the Developer's Console. To be able to cheat at all, you must first type in "sv_cheats 1" Also, keyboard Bind are possible with the Bind console command. i.e. If you type bind x "sv_cheats 1" into the console, if you press X on your keyboard, cheats will activate automatically.

Activate Cheat Mode: sv_cheats 1
Bullet Time Macro. Allows control of the flow of time.
1 is default speed. 2 is Fast Foward. 0.5 or 0.75 is Slo-Mo.: host_timescale
Deactivate Cheat Mode: sv_cheats 0
Infinite Run/PsiForce: sv_infinite_aux_power 1
Normal Run/PsiForce: sv_infinite_aux_power 0
Refill Ammo (Ignores Inventory and Speed Bonus/Malus): givecurrentammo
Switch to First Person View: firstperson
Switch to Third Person View: thirdperson
Switch to Third Person View with different WASD/Mouse control scheme : thirdperson_platformer 1