The following codes have no effect until you complete both levels with a five star rank on the hardcore difficulty setting to unlock them. Each code has two parts, each of which are unlocked by a specific two levels (for example, completing the Trained to Kill and Border Patrol levels with a five star rank unlocks the "Invisibility" cheat). When this is done, one half of a code will appear at the bottom of the image that is now unlocked in the "Bonus Features" menu. Once both halves (images) are unlocked, that specific code can now be activated in any level in the game.