Here is the full list of all 34 Zombie Night Terror achievements.
¯\_(ツ)_/¯
Create a level and upload it to Steam Workshop
Start the level editor
Kill 10,000 humans
Scare 6 humans with a single scream
Spend 104 minutes on the Credits page
Successfully complete all challenges
Assemble a horde of 12 zombies with a screaming Overlord
Be patient!
Defeat the Boss in Chapter 4
Successfully complete all levels
Let a Tank get squashed
Collect 1,000 DNA units
Defeat the Boss in Chapter 3
Bite 1,337 humans to death
Paint over 9,000 blocks with blood
Kill a zombie by blowing up another zombie nearby
Let 1,000 zombies die
Collect 100 Mutation Barrels
Defeat the Boss in Chapter 2
Kill 50 cops
Blow up 4 humans with a single explosion
Blast through 256 breakable blocks
Kill 7 enemies with a single Tank dash
Kill Gronald
Fall with style for at least 10 seconds with a zombie
Defeat the Boss in Chapter 1
Prevent a zombie from falling to its death by blowing up another zombie
Let 66 zombies fall to their death
Kill a zombie by making him jump from too high
Lose a level by sacrificing your last zombie
Destroy 28 doors
Use 5 contaminations on humans
Bite 10 humans to death in 15 seconds