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