Here is the full list of all 14 Stitched achievements.
Unlocked the true ending
Unlocked the alternate ending
Unlocked the bad ending
Uncovered the identity of the dark figure
Put the puzzle pieces together and solved the sliding puzzle
Unlocked the sun and moon safes
Visited all locations shown on the map
Deciphered the message of the two sisters
Solved the card puzzle in the prison
Solved the sliding puzzle on the fourth floor
Caused Catherine's heart to stop beating
Unlocked the secret ending