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