Here is the full list of all 21 20 Minute Metropolis - there are The Action City Builder achievements.
Reach 1 Point in the Final Level
Reach 250,000 Points in the Final Level
Reach 750,000 Points in the Final Level
Reach 1,500,000 Points in the Final Level
Reach 2,500,000 Points in the Final Level
Stockpile 200 Wood at Once
Stockpile 110 Plastics at Once
Stockpile 4000 Stone at Once
Stockpile 300 Metals at Once
Complete the Main Level
Complete the "Connections" Lesson
Complete the "Conveyance and Blocking" Lesson
Complete the "Food to Work to Wood" Lesson
Complete the "Stacking Tiles" Lesson
Complete the "Waste Management" Lesson
Complete the "Stored Resources" Lesson
Complete the "Ruins" Lesson
Complete the "Mountains & Digs" Lesson
Complete the "Energy" Lesson
Complete the "Transmitters" Lesson
Complete the "Parks and Points" Lesson