Defeat 20 enemies with headshots

Defeat 20 enemies with hand-to-hand combat

Answer a ringing phone

There is only one way in

Save the damsel, but is she in distress?

Make Santa and his reindeer fly

Kill 5+ Hybrids at once by using the HE .44 Magnum secondary fire

Complete Campaign Mode on any difficulty

Collect 50% of the journals

Use the upgraded Rossmore secondary fire to set 6 enemies on fire at once

Get a kill with every weapon in your arsenal

Get 50 headshot kills in Campaign Mode