Here is the full list of all 20 NecroWorm achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Eat 40 eyes
Eat 30 brains
Eat 20 skulls
Earn 350 points
Earn 300 points
Complete 120 levels
Complete game
Earn 200 points
Complete 80 levels
Earn 150 points
Complete 60 levels
Earn 100 points
Complete 40 levels
Earn 60 points
Complete 20 levels
Earn 30 points
Earn 10 points
Complete first bonus level
Complete any level under 5 sec
Complete first level