Cheat Codes
     While  playing,  hold [CTRL] + [SHIFT] + [O] + [E] and then press 
[H]  to  activate  Developer  mode.  You  can  then  press  any of 
the  following cheat keys. 

8: Add 1000 EXP

6: Give Explosives

5: Give Gas Mask

9: Give Morphine

2: Give Next Handgun

1: Give Next Rifle

G: God Mode

7: Intended Upgrade Attributes

N: Maximum Ammo for Current Weapon

M: Maximum Armor

X: Toggle Fly Mode

V: Toggle Visibility



Cheat Method
     Browse   to   your  Velvet  Assassin\aio\  folder  and  open  the
difficulty.cfg file using Notepad. You can alter any of the entries in
this file to suit your needs. For example, change:

NPCDamage = 1 

to 

NPCDamage = 0 

     ...for  Invulnerability. Note that you can also alter other files
in this folder such as weapons.cfg to make further adjustments to your
game.