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