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.
Jump off the rooftop.
Talk with Library multiple times.
Free Kurata in the Truth route.
Clear Truth with the female protagonist.
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.
Check your key items.
Hide in a cardboard box.
Refuse to help Yoshino.
Save Kudoh.
Read "The Lazy-Eyed Ranger."
Read the diary in the library.
Encounter Hanako.
Get a whiff of a toilet.
Have a meal.
Make a quicksave.