Here is the full list of all 14 Melatonin achievements.
Get through night 1
Score 3 rings in a level
Get a perfect score in scored mode
Score 3 stars in a level
Get through night 2
Get through night 3
Get through night 4
Get through the morning
Perfect the tutorial
Get a perfect score in hard mode
Collect all stars in the game
Collect all rings in the game
Get all perfect scores
Finish a custom edited level