Save all humans on Acis

Drain the Sewers

Purchase all skills in one category.

Complete one challenge.

Find 25% of GPS caches.

Kill 25 unaware enemies.

Kill 50 enemies with the bow.

Kill 75 enemies with the rifle.

Perform 50 headshot kills in the single player campaign.

Perform 15 finishers.

Force an enemy to drop dynamite that kills two people when exploding.

Complete one optional tomb.

In the Main Campaign, completed Lighthouse.