Kill 35 enemies with the pistol.

Defeat any boss in Adventure Mode without using a Drone Super or a Smart Bomb

Score at least 1 million points on any level in Adventure Mode

Find 75% of GPS caches.

Collect 75% of all relics.

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

Complete one challenge.

Kill 75 enemies with the rifle.

Collect 5000 pieces of salvage.

Perform 50 headshot kills in the single player campaign.

Collect 25% of all relics.

Kill 50 enemies with the bow.

Complete one optional tomb.