To unlock certain cheats (such as infinite health, infinite ammunition and more), and to unlock a plethora of concept art from the game’s development, complete the game once through in its entirety.
Completion bonuses
Complete campaign mode to unlock the following.
Unlimited health,Unlimited grenades and double your health regeneration - Complete the game
Environmental character and weapon concept art at the extras menu - Complete the game
Level select
Select "Extras" at the main menu. Select "Bonus Codes" then "Enter a Bonus Code". Enter UM3N8TTQE58BW0 as a code.
Unlimited grenades
Select "Extras" at the main menu. Select "Bonus Codes" then "Enter a Bonus Code". Enter GH7W4YT9EWEHDD as a code.