You can bring down the console in Soldier of Fortune II by pressing and holding the SHIFT key and then pressing the ~ (tilde) key. Do the same to put the console back up.
How to enable cheats
Bring down the console and type "sv_cheats 1" (minus the quotes) and press ENTER. You can also type
map to load a specific map and have the cheats enabled once the map loads. sv_cheats 1 is write protected in the regular single player game. You need to load a map first using the map or devmap command. So you would type map pra1 or devmap pra1 at the console and hit enter. When the map loads, use sv_cheats 1 and hit enter to enable the cheats.
All levels Selecter
Bring down the console and type this command: raven 1
Then all levels will be selectable from the menu....enjoy !
Various Cheats
Before loading the level, at the main menu, press ~, and type "sv_cheats 1"
Then type the following in game:
notarget - no enemy fire
god - god mode
give all - gives everything
noclip - walk trough walls
Multiple Cheats
Result - Cheat Code
God mode - /god
Disable enemy AI - /notarget
No clipping mode - /noclip
All weapons and ammunition - /give all
Armor - /give armor
Full ammunition for current weapons - /give ammo
Health - /give health
Stamina - /give stamina
Spawn indicated item - /give [item name]
Never get tired - /nofatigue
Display current map name - /mapname
List maps - /dir maps
Advance to indicated map - /spdevmap or /devmap [map name]
Show all commands - /cmdlist
Reconnect to last server - /reconnect
Suicide - /kill
Exit game - /quit