Here is the full list of all 66 Chronotopia: Second Skin achievements.
Meet Berthe
Be mean to Fleur
Have an argument
Help with farm work
Meet Fleur
Unlock the dead end
The beginning of a long nightmare
Find memory fragment n°2
Obtain the whistle
Heed the mad king’s words
Visit the fairy tale
Wake up in purgatory
Find memory fragment n°1
Be nice to Fleur
Complete the washing place’s storyline
Complete the kitchen’s storyline
Complete the corridors’ storyline
Complete no storyline
Meet Griselde
Meet Thalie
Succeed with the socialization task
Fail the socialization task
Succeed with the management task
Fail the management task
Succeed with the embroidery task
Fail the embroidery task
Meet Georges
Search the room for clues
Find memory fragment n°3
Meet Genèse
Visit Genoa for the 1st time
Meet an old friend
Divination by the entrails
Find memory fragment n°4
Unlock Kionna’s Bad Ending
Choose Nahima
Unlock Nahima’s Bad Ending
Unlock Nahima’s Ending 1
Unlock Nahima’s Ending 2
Choose Médeia
Unlock Médeia’s Bad Ending
Unlock Médeia’s Ending 1
Unlock Médeia’s Ending 2
Choose uncertainty
Meet Aalis
Meet the Acelin family
Solitude by the window
Unlock ???’s Bad Ending
Guess who's back, back again?
Unlock ???’s Ending 1
Unlock ???’s Ending 2
In case you forgot
Unlock the soul’s Bad Ending (no fragment)
Unlock the soul’s Neutral Ending
Unlock the soul’s Good Ending (all fragments)
Unlock all of the illustrations
Unlock all of the archives
Find all elemental spirits