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