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 male protagonist.
Clear the main game with the male protagonist.
Talk with Library multiple times.
Hide in a cardboard box.
Clear Truth with the female protagonist.
Free Kurata in the Truth route.
Give Misao some coins
Clear the main game with the female protagonist
See the bad ending.
Find the message in the back of the laboratory.
Play the piano.
Save Kudoh.
Encounter Hanako.
Refuse to help Yoshino.
Jump off the rooftop.
Have a meal.
Get a whiff of a toilet.
Read the diary in the library.
Read "The Lazy-Eyed Ranger."
Check your key items.
Make a quicksave.