Throw back a grenade and defeat two enemies at once

Defeat 20 enemies by blind-firing while in cover (without aiming with L1/R1)

Finish the game in Normal Mode

Defeat 30 enemies with the Tau Sniper

Defeat 30 enemies with the M9

Find 80 treasures

Defeat 30 enemies with the Mk-NDI

Find 60 treasures

Defeat 20 enemies with gunfire by aiming while hanging

Find 40 treasures

Defeat 50 enemies with hand-to-hand combat

Defeat 20 enemies with hand-to-hand combat

Complete Chapter 4 in Jake's campaign.