Here is the full list of all 13 Numberline achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Complete 60 levels
Complete 55 levels
Complete 50 levels
Complete 45 levels
Complete 40 levels
Complete 35 levels
Complete 30 levels
Complete 25 levels
Complete 20 levels
Complete 15 levels
Complete 10 levels
Complete 5 levels
Complete your first level