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