Throw Back a Grenade and Defeat 2 Enemies at Once

Completed chapter 12.

Kill 30 Enemies with the SAS-12

Completed chapter 10.

Headshot an enemy with an arrow from a distance beyond 25m

Completed chapter 7.

Kill 50 Enemies by Melee-Attacking from Behind

Kill 10 Enemies with Grenades While Hanging

Kill 20 Enemies by Shooting from the Hip (without aiming)

Defeat 20 Enemies While Swimming

Complete any Challenge Tomb

Completed chapter 6.

Enter the Syrian tomb