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