Here is the full list of all 18 Between Me and The Night achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Finish the high school level.
Finish the apartment level.
Finish the game.
Clean up the broken objects in the apartment.
Complete the Thunder Rangers poster in the High School.
Find the 3 strange medicine bottles.
Complete the house without being caught by any ghost.
Listen to all the cassettes.
Get to the end of 1000 Knights.
Let the Keykeeper catch you while holding the hall pass.
Don’t get hit by enemies while in the Otherworld.
Finish the house level.
Put all the soldier and knight toys in their respective bases, in the House.
Enter the Otherworld for the first time.
Complete level 3 of Generic Knight.
Finish the tutorial.