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.
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 Plasma gun.
Kill at least 1,000 zombies with a flare gun.
Kill at least 1,000 zombies with a Pepyaka gun.
Kill at least 1,000 zombies with a Spread gun.
Kill at least 1,000 zombies with a Volcano machine gun.
Perform a rampage attack.
Kill the first Undead Boss.
