Pasted from a comment from one of the devs

Console is accessed via "~" as you'd expect.

slomo [value]
Changes the speed of the game, default is 1

zhenme [value]
Sets how much money you have

sas (also noclip works)
NoClip mode (its stupid, I just did it since its fast to type)

giveall
Gives all weapons and ammo

neverrunout
Never run out of ammo

notrigger
Enemies don't react to you

tornado
God mode

hidehud/showhud
Does what you'd expect

givekeys
Gives all weapons and keys