The only achievement for this game is unlocked after you finish the story and reach the credits. There are no other requirements and the game can be completed anywhere from 4-6 hours, depending how fast you read text and solve the puzzles (it took me around 5 hours). I won't spoil the story, but I suggest you take your time and read as much dialogue and text as possible from all the characters you meet. FYI you may miss the achievement unlocked popup notification if you have tears in your eyes.
