Defeat the Goliath in the single player Campaign.

Kill five enemies in a row with a brutal combo

Finish the game in Easy Mode

Kill three enemies with one explosion

Kill 50 enemies with the M4

Kill 20 enemies with the Desert - 5

Kill 20 enemies with a brutal combo

Kill 20 enemies by shooting from the hip (without aiming with the L1 button)

Kill 20 enemies with the Wes - 44

Find the Strange Relic

Kill 50 enemies with the PM - 9mm

Find five treasures