Complete Act IV.
Finish the game on Easy difficulty.
Complete Act III.
Kill a total of 30 enemies with Browning gun.
Complete Act II.
Deliver 100 headshots.
Kill 10 enemies with throwing knives.
Kill 2 enemies with one shot.
Kill 2 enemies with one grenade.
Shoot 5 cable lines using sniper rifles.
Kill all enemies attacking your pontoon from the riverside on "Weaken The Regime" level.
Complete Act I.
Shoot an enemy through a wall.
Deliver 50 headshots.
Kill 15 enemies using concentration mode.
Finish the game on Normal difficulty.
Finish the game on Hard difficulty.
Collect all secrets.
Kill 250 people using pistol.(Multiplayer)
Kill 250 people using sniper rifle.(Multiplayer)
Kill 500 people using sniper rifle.(Multiplayer)
Kill 2000 people.(Multiplayer)
Win 50 rounds playing online.(Multiplayer)
Kill 10 birds.