During play, hold G + O + D to display the command line. Now enter the following codes:

IMMORTAL - God mode on
MORTAL - God mode off
RETICLE - Smart Reticle; turns red when over a target
CAMERA - Third person view when on-foot
ALLAMMO - All on-foot weapons have max ammo
TARGETS - Targeting for on-foot weapons
DMDAMAGE - Double damage when on-foot
RADAR - On-foot radar
CW - All car weapons
CA - Max car ammo
STONEAGE - Running person in place of car
CAROFF - No car geometry
CARFLIP - Flip car geometry
CARREVERSE - Reverse car geometry
WHEELSOFF - Toggle car wheels