Here is the full list of all 27 The Crooked Man achievements.
Escape the gas with over 1 minute to spare
Defeat the Crooked Man in Scene 2 without taking any damage
Don't miss a single shot at the Crooked Man
Beat the game twice
Go back to bed without answering the phone
Finish the Prologue
Read the books in the hotel library
Survive first encounter with the Crooked Man
Get Game Over once
Get Game Over 5 times
Defeat the Crooked Man in Scene 1 without taking any damage
Get Bad Ending 1
Finish Scene 1
Read the books in the school
Get killed by poison gas
Try to enter D's bed
Try to enter the bed next to D's bed
Get Bad Ending 2
Finish Scene 2
Read the books in the hospital day-room
You shot Fluffy
Finish Scene 3
Get Bad Ending 3
Get Bad Ending 4
Finish Scene 4
Beat the game without drinking the energy drink
Beat the game once