Start the game by running the game from your RUN menu with:
"C:GameFoldershift.exe" -console 

Now you can bring down the console command box at any time during the game with the ~ key (tilde). Now before loading a map or game, you must open your console and type "sv_cheats 1" (excluding ""). Alternatively you may place the command in your "C:GameFolderconfig.cfg" file with notepad, so it will be automatically set next time you open the game. 

You may now use the following commands (excluding ""): 

"god" - God Mode 

"notarget" - No Target Mode 

"noclip" - NOCLIP Mode : Fly through walls 

"impulse 101" - Gives all weapons 

"sv_gravity x" - Adjusts Gravity where when X = 800 the game uses default gravity and when X = 0 there is no gravity. 

"sv_accelerate x" - Adjusts air acceleration so you move more when you jump. Default = 10 but increase for more effective bunnyhopping :) 

"skill x" - Adjusts skill in-game, 1 = Easiest, 3 = Hardest. 

"map x" - Replace X with one of the following maps: 

ba_canal1
ba_canal1b
ba_canal2
ba_canal3
ba_elevator
ba_hazard1
ba_hazard2
ba_hazard3
ba_hazard4
ba_hazard5
ba_hazard6
ba_maint
ba_outro
ba_power1
ba_power2
ba_security1
ba_security2
ba_teleport1
ba_teleport2
ba_tram1
ba_tram2
ba_tram3
ba_xen1
ba_xen2
ba_xen3
ba_xen4
ba_xen5
ba_xen6
ba_yard1
ba_yard2
ba_yard3
ba_yard3a
ba_yard3b
ba_yard4
ba_yard4a
ba_yard5
ba_yard5a