Here is the full list of all 42 Rebuild 3: Gangs of Deadsville achievements.
Kill 100,000 zombies cumulatively
Discover the true origin of the disease
Have 100 survivors at once
Eat enough people to be considered evil cannibals
Become Gustav's friend and get his special deals
Complete the Return to New York questline
Complete the Gangs of Deadsville questline
Equip every survivor with a gun
Complete the final scenario city
Use 50 bath salts in one game
Finish any city by day 50
Repair an airplane and fly away
Have 365 food at once
Get any survivor to defense level 20 (includes equipment)
Complete every research project
Fully infect the Dahlias with your cultists
Complete the Pig Farmer questline
Declare peace with a faction
Have 50% of survivors become cultists
Light off Fireworks
Have 5 hospitals, 10 medkits, and 100 medicine at once
Equip 10 animals
Finish any city on Hard difficulty
Be allies with every faction in the city
Have a survivor with 10 in every skill
Find 100 items while scavenging cumulatively
Reclaim the entire city
Destroy every faction on the map
Kill 10,000 zombies cumulatively
Fix a Power Plant
Destroy any faction
Become allies with any faction
Produce 100 items in the workshop cumulatively
Generate a surplus of 50 food per day from farms
Equip a Rocket Launcher
Finish any city on Impossible difficulty
Complete scenario city 1
Finish any city on any difficulty
Build a City Hall
Kill 1000 zombies cumulatively
Kill 100 zombies cumulatively
Get any survivor to level 10 in some skill