Defeat 50 enemies with stealth attacks

Defeat five Riot Shield enemies by running over their shield

Defeat five enemies in a row using stealth attacks

Defeat ten enemies using hand-to-hand combat on the back of the convoy trucks

Defeat 30 enemies in a row with your side arm

Defeat 20 enemies while swimming

Defeat 30 enemies with the Tau Sniper

Complete one Cooperative Multiplayer game

Defeat 20 enemies by shooting from the hip (without aiming with L1/R1)

Defeat five enemies in a row with headshots

Find 80 treasures

Defeat 30 enemies with the T-Bolt Sniper

Defeat 100 enemies with headshots