Here is the full list of all 15 Post-Apo Builder Demo achievements.
Destroy enemy at the location
Send your first expedition
Build any vechicle
Build bug farm
rebuild destroyed bridge
Win demo
First death of citizen
Poison the tribal people
Have 36 people join the community
Build main gate
Build a solar panel
Build a Doll House
Unlock the 2 tech level
Complete the tutorial
Build a water windmill