Find all the volunteer's voice recordings

Finish all quests in the game

Kill 10 monsters with one mine

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

Find 50% of collectibles

Kill the Skeleton King in Normal mode.

Kill one of the unique enemies listed in the Never Seen That Before Challenge.

Kill 100 enemies using charge attacks

Complete all the main quests cooperatively with any number of partners

Kill 100 monsters with thrown melee weapons

Finish a match against a Friend in FIFA 12 Ultimate Team

Defeat Harlow

Make pact with Serpo