Yea on the room on the right there's a paper that hints at what you have to do. After looking at it look at the painting in the middle room and it will become apparent!
I wish you luck with your game and any future ones you plan to make!
Thanks for the hint, but I was just calculating the code wrong, got it eventually! Such a sad story :( well done on it though! And I had a laugh about the big text in one of those last rooms.
And thank you, good luck to you and your future games too! I definitely can see the potential for a more elaborate puzzle game from this :)