Here is the full list of all 31 Infected Shelter achievements.
Complete the Tutorial.
Open a huge treasure chest for the first time.
Have 3 labrador puppies at the same time.
Grab and throw an enemy for the first time.
Buy all items in a shop.
Defeat 99 elite enemies.
Defeat a boss in co-op mode.
Revive a co-op player.
Rescue five camp people.
Defeat the Walker Droid boss.
Defeat the Attack Copter boss.
Defeat the Mutant Bison boss.
Defeat a boss without taking damage.
Unlock 99 blueprints.
Unlock 9 weapons.
Unlock 9 relics.
Unlock 9 skills.
Unlock 9 clothings.
Unlock 9 improvements.
Explode 99 cars.
Defeat any boss without using any skills.
Make noxious gases during jump.
Have 499 golden badges at one time.
Have 999 infection samples at one time.
Execute an enemy with a tear-gas grenade.
Execute an enemy with an acid bottle.
Execute an enemy with a lamp.
Kill a boss only with unarmed attacks.
Die in the tutorial.
Reach the desert for the first time.
Find the Biologist