Here is the full list of all 21 Misao: Definitive Edition achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Clear Truth with the female protagonist.
Free Kurata in the Truth route.
Clear the main game with the female protagonist
Find the message in the back of the laboratory.
Read the diary in the library.
Refuse to help Yoshino.
Clear Truth with the male protagonist.
See the bad ending.
Give Misao some coins
Clear the main game with the male protagonist.
Play the piano.
Save Kudoh.
Talk with Library multiple times.
Check your key items.
Jump off the rooftop.
Hide in a cardboard box.
Encounter Hanako.
Get a whiff of a toilet.
Have a meal.
Read "The Lazy-Eyed Ranger."
Make a quicksave.