Singleplayer: Get a total of 30 pistol kills

Finish the game

Enter the docks in Quarantine Zone

Make pact with Serpo

Find all the volunteer's voice recordings

Finish hospital quests for Cecil

Clear out the cinema

Kill 100 enemies using charge attacks

Finish quests for Dr. Kessler

Kill 100 monsters with thrown melee weapons

Kill 10 monsters with one mine

Kill special enemies: Grenadier, Thug, Wrestler, Infected, Suicider, Screamer, Butcher, Floater.