Use melee attack 100 times in one session.

Kill 500,000 zombies.

Rack up to 30 level.

Explode at least 100 cars in one session.

Performed a rampage attack.

Killed ?the ?first Undead Boss.

Don't shoot for whole six minutes and survive.

?Score 10,000,000 experience points in ?a single session.

Stay alive at least 60 minutes.

Kill at least 1,000 zombies with a pistol.

Kill at least 1,000 zombies with a revolver.

Kill at least 1,000 zombies with an Uzi.

Kill at least 1,000 zombies with a shotgun.

Kill at least 1,000 zombies with an M-16.

Kill at least 1,000 zombies with an M-60.

Kill at least 1,000 zombies with a crossbow.

Kill at least 1,000 zombies with a ?P?lasma gun.

Kill at least 1,000 zombies with a flare gun.

Kill at least 1,000 zombies with a ?P?epyaka gun.

Kill at least 1,000 zombies with a ?S?pread gun.

Kill at least 1,000 zombies with a Volcano machine gun.