Here is the full list of all 21 SurrounDead achievements.
Take out a zombie boss.
Break a bone from a high fall.
Traverse for 10km with one character.
Take out a human survivor.
Cause the death of your player.
Use a medical item on the player.
Play 'Survival'.
Find & drive a vehicle.
Place down a buildable.
Gain access to a secure area.
Play SurrounDead during Early Access release.
Traverse for 100km with one character.
Take out 500 zombies with one character.
Take out 5000 zombies with one character.
Take out 100 human survivors with one character.
Gain access to a hidden secure laboratory.
Take out 10 zombies bosses.
**REDACTED**
Take out 50 animals.
Take out 200 animals.
Catch a fish.