Here is the full list of all 15 Demolition Engineer achievements.
Upgrade all stats to the max
Complete level 5
Complete the game
Complete level 4
Destroy 30 buildings
Complete level 3
Complete level 2
Repaint the machine
Earn 100 coins
Complete level 1
Destroy your first building
Destroy 100 buildings
Earn 500 coins
Earn 1000 coins
Unlock all styles of painting