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