Full list of all 21 #KILLALLZOMBIES achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
Killed at least 1,000 zombies with an M-60.
Used melee attack 100 times in one session.
Killed at least 1,000 zombies with an M-16.
Killed at least 1,000 zombies with a crossbow.
Killed at least 1,000 zombies with a Spread gun.
Killed at least 1,000 zombies with a Plasma gun.
Killed at least 1,000 zombies with a Pepyaka gun.
Killed at least 1,000 zombies with a revolver.
Killed at least 1,000 zombies with a pistol.
Killed at least 1,000 zombies with a Volcano machine gun.
Killed at least 1,000 zombies with a flare gun.
Killed at least 1,000 zombies with a shotgun.
Killed at least 1,000 zombies with an Uzi.
Performed a rampage attack.
Kill 500,000 zombies.
Rack up to 30 level.
Explode at least 100 cars in one session.
Kill 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.