Kill 50 Enemies by Melee-Attacking from Behind

Throw Back a Grenade and Defeat 2 Enemies at Once

Defeat 20 Enemies by Blind-Firing While in Cover (without aiming)

Kill 30 Enemies with the T-Bolt Sniper

Kill 5 Enemies in a Row with Headshots

Successfully Counter all of a Brute's Damage-Giving Attacks

Kill 30 Enemies with the Tau Sniper

Kill 30 Enemies with the G-MAL

Kill an Enemy While Playing as an Alternate Character Costume Other Than Drake

Hit 3 Enemies with Fish in the Market

Kill 30 Enemies with the SAS-12

Find all Treasures and the Strange Relic

Kill 30 Enemies with the M9