Found 50% of the documents in the game.

Obtain five extremely rare weapons.

Pass the Research Facility without killing a Blind One on the DEAD CITY level.

Kill 300 mutants.

Max out the research level (up to high rank) for many monsters.

Take part in the Admiral's tea party on the TAIGA level.

Kill 300 human enemies.

Campaign: Collected all shotguns models.

Completed 3 missions with another player.

Find a tune on the radio.

After running out of filters in a hazard zone, craft a new one while suffocating.

Defeat Olaf, the Skellige champion of unarmed combat.

Slide downhill uninterrupted for at least 10 seconds.