Fully mod and completely upgrade any weapon.

Kill 75 enemies with the rifle.

Purchase all skills in one category.

Force an enemy to drop dynamite that kills two people when exploding.

Collect 25% of all relics.

Kill and loot 10 flying animals (crows and gulls).

In multiplayer, be the only player on your team that isn't dead or downed.

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

Meet the Guru

Climb from the pit of Hades

Destroy pumps

Kill 250 zombies using blunt melee weapons.