In order to do this you have to clear the game + the 6 puzzle pieces +the 2 extra achievements ( the books and the Hanoi tower ).
The bug that prevents the achievement to pop for a lot of people works like this:
When you exit the game you lose all your progress with the exception of saved games. What does that mean towards the achievement : if you had finished the game with all 6 puzzle pieces enter that save game and finish it again ( you now have the clearing the game + 6 puzzle pieces ); you still have the hanoi tower ( chapter 8-1) and the books, but for the books you will have to return to every chapter that includes the Chalet and read all the books plus Carto's book ( sometimes Carto's book must be read multiple times as it changes before and after the task in hand ).
So it isn't required to finish it in one sitting in theory, but i recommend that you do it without exiting the game. Took me around 2 hours.
A full and fast achievements guide in the video.