Using a text editor edit the 'hitmancontracts.ini' file in the game folder by adding 'EnableCheats 1' to the end of it then during gameplay press Shift + Escape and enter the following codes to unlock the corresponding effect.
Enables God Mode: God 1
Disable God Mode: God 0
Gives you ALL Weapons and Items: Giveall
Gives you Infinite Ammo for ALL Guns: Infammo
Enables Nail Gun: Nailgun 1
Disable Nail Gun: Nailgun 0
Makes you Invisible to Enemies: Invisible 1
Deactivates Invisibility: Invisible 0
Unlockable Weapons Weapons are unlocked by completing the corresponding mission and getting the Silent Assassin rating.
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "hitmancontracts.ini" file in the game folder. Add the following lines to the end of the file. EnableCheats 1 EnableConsole 1 Then, press ~ during game play to display the console window. Enter one of the following codes at the console window to activate the corresponding cheat function.
Effect - Code God mode - god 1 Invisibility - invisible 1 All weapons and items - giveall Level skip - end level Unlimited ammunition - infammo