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