Complete the indicated task to unlock the corresponding character.

Airplane Bodyguard: Complete Headshot mode.
Brummel: Defeat Brummel during game play.
The Immortal: Defeat The Immortal during game play.
Nightmare: Complete Close Combat mode.
The Original Spider: Defeat The Original Spider during game play.
The Russian: Defeat The Russian during game play.
SWAT Leader: Defeat SWAT Leader during game play.