Drop in on an old friend

There is only one way in

Save the medical volunteers

Become the Bat

In Shadows of Evil, spot the Shadowman fives times in one game.

In Campaign, kill an enemy through a wall or obstruction.

Kill 50 Enemies by Melee-Attacking from Behind

Kill 100 Enemies with Headshots

Kill 50 Enemies with the M4

Defeat 50 Enemies with Hand-to-Hand Combat

Kill 20 Enemies with Headshots

Defeat 20 Enemies with Hand-to-Hand Combat

Finish the Game on Normal Without Changing the Difficulty