Here is the full list of all 21 Au-Delà achievements.
Die before leaving the beginning room.
Hide in the library when the monster sings his lullaby.
Finish the tutorial.
Speak 50 times with the narrator.
Collect all the drawings.
After the tutorial, finish the game without saving.
After getting the flashlight, complete the game without turning on the light.
Attack all monsters with the watergun.
Cut the hair of all the dolls
Finish the game without the cart