Kill 5 Infected in a row with a single blow.

Complete 5 quests with 3 co-op partners.

Play with 10 different co-op partners for at least 15 minutes each.

Complete act IV.

Complete act III.

Kill 250 zombies with modified weapons.

Kill 25 zombies with your bare fists.

Kill 50 human enemies.

Reach level 25.

Complete act I.

Create weapons to rival the gods of fire or thunder.

Create a customized weapon.