Kill 250 zombies using blunt melee weapons.

Kill 50 human enemies.

Save 5 people besieged by zombies.

Play in a co-op team of 4 different playable characters.

Kill an Infected with a grenade blast.

Sever 100 limbs.

Breach a locked door with the first blow.

Drive a total distance of 10 kilometers.

Complete 25 quests while playing with at least one co-op partner.

Complete act I.

Travel a distance of 20 kilometers on foot.

Create a customized weapon.