Full list of all 68 Zombie Army Trilogy achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
Achieved an unbroken 10-headshot streak
Army of Darkness completed
Acquired the Preacher
The Keep completed
Shot a Suicide Zombie's grenade – that'll teach him
Forest of Corpses completed
Showed a Zombie Sniper how it's done – got him in mid-air
Killed at least 500 enemies with headshots
Freight Train of Fear completed
City of Ashes completed
Committed foul murder
Tower of Hellfire completed
Terminal completed
Got at least 15 enemies with one explosion
Got at least 10 enemies with one explosion
Crucible of Evil completed
Over 1,000 limbs lopped
Answered a phone call from Hell. It was a wrong number
Gateway to Hell completed
Killed at least 20 enemies while incapacitated
Acquired a Panzerfaust
Got a headshot on a Heavy Armour Zombie without removing his helmet first
Lightened a Super Elite's wallet
Purgatory completed
Prevented at least 20 enemies from getting up
Investigated a possessed doll and lived to regret it
Raised your Chain Count to at least 10
Subway to Hell completed
Library of Evil completed
Labyrinth of Death completed
Put the boot into at least 50 enemies
Successfully complete Village of the Dead
Successfully complete Cathedral of Resurrection
Successfully complete all Chapters on Sniper Elite difficulty
Kill an Occult General
Loot a Chainsaw Elite's corpse
Save the man in the hospital
Put the tortured souls in the Forest out of their misery
Shoot the 3 Zombie Ravens outside the Folterschloss
Complete any Campaign chapter in 4-player co-op at any difficulty level
Kill 5000 enemies of any kind
Kill 500 Skeletons
Kill 100 Zombie Snipers
Kill 50 Suicide Zombies
Kill 50 Super Elites
Kill 25 Fire Demons
Kill 25 Summoners
Get a 5-for-1 kill with any sniper rifle
Reach a total shot distance of 50km
Sever 10,000 limbs
Get at least 20 for 1 with an explosive kill
Score 5,000 with a single sniper round
Reach a Chain Count of 20
Reach a Chain Count of 30
Reach at least Wave 10 in Horde Mode – Waves of Despair
Reach at least Wave 10 in Horde Mode – No Sanctuary
Reach at least Wave 10 in Horde Mode – Flood of Tears
Reach at least Wave 10 with the highest score in any Horde Mode map
Reach at least Wave 10 with more gold medals than your companions
Kill 50 enemies that are actively attacking other players
Revive other players 50 times
Kill 20 Elites in co-op
Complete every Survivor sidequest
Complete levels as every playable character
Collect every Gold Bar
Find and shoot every Bottle of Blood
Reach at least Wave 10 in Horde Mode – Dead End
Reach at least Wave 10 in Horde Mode – Dead Man's Bluff