Here is the full list of all 35 The Last Stand: Aftermath achievements.
Kill 1000 Infected
Trigger a trap, with fatal consequences
Died 10 times
Purchase an item from the travelling merchant
Spend Knowledge points to max out a skill upgrade
Reach Level 10
Survive in No Man's Land
Collect 100 Knowledge
Acquire a mutation
Survive a Horde
Craft an improvised weapon
Craft an item at a crafting station
Kill a Volunteer
Interact with a Supply Cache
Complete the tutorial
Reach The Mountains
Reach The Sunken City
Reach Hell
Reach Level 50
Reach Level 100
Kill a Charger
Kill a Spitter
Kill a Leaper
Kill a Burster
Kill a Flamer
Kill an Armored Charger
Discover the modified HERC device
Open the gates at the HERC checkpoint
Activate the radio tower
Lower the bridge in Leighton City
Complete the main quest line
Complete 5 Runs
Craft 25 items at a crafting stations
Collect 25 Supply Bags
Use Antiviral 25 times