Install a modification of each category on a single weapon.

Get into a boat.

Complete the MOSCOW level.

Collect 5000 pieces of salvage.

Perform 50 headshot kills in the single player campaign.

Kill 50 enemies with the bow.

Complete 10 Secret Missions

Complete one challenge.

Kill and loot 10 large animals (deer, boar, wolves).

Acquire Aquila

Help Phineas retrieve his eye

Finish "Secret Ingredient" while killing all of the enemies during the descent