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