Could you give me a clue on the second room with the chess board please?
I found 3 books but couldn't make any connection between them and the rows/columns to obtain a number for the door code.
Often I would start moving without touching anything. This would be sideways mostly but occasionally down or up. Going up allowed me to pass through the ceiling and simply walk to the end where the lava room is. I can see that you can flip the stones for some reason but you can simply teleport between the stones and reach the ladder?