At start, in the game window type "arno", then the confirmation will appear only after you activate the following codes:
Ctrl + F3: Freeze all on/off
Ctrl + F4: God Mode on/off
Ctrl + F4: More ammo (you can repeat for getting more)
Shift + F4: Invisibility
Shift + F10: Location of the pointer
Ctrl + F12: Complete successfully the current mission