Here is the full list of all 28 Along the Edge achievements.
Let Clothilde convince you to break up with Frank
Accept Clothilde's deal without being in a relationship with Stanislas
Help Yves Malterre break the curse
Chat with everyone at the cocktail
Spend the night with Frank, then Stan
Spend the night with Stan
Yves Malterre sacrifices himself to break the curse
Listen to Stan's advice
Accept Clothilde's deal while being in a relationship with Stanislas
Sophie Delatour dies
Finish the game with a majority of "Sun" and "Star" choices
Finish the game with a majority of "Moon" and "Globe" choices
Be romantically involved with Stanislas at the end of the game
Spend the night with Frank
Choose not to call your therapist
Cut your hair short
Listen to Frank's advice
Be romantically involved with Frank at the end of the game
Let Yves Malterre get into the tower
Finish the game with a majority of "Sun" and "Globe" choices
Play it "hard to catch"
Have a conversation with your Grandmother
Be friends with Solène at the end of the game
Finish the game by obliterating the Malterre family
Witness the fire at the Castle
Have a mystical encounter in the forest
Be single at the end of the game
Finish the game with a majority of "Moon" and "Star" choices