I must say that I am rather intrigued by the story related to Kristof. Indeed I could see that there were several images in the image folder of the game illustrating the scene when it is discovered in the cave.
So I searched in vain how to find it but I guess that to access it, it will be necessary to wait for a next version of the game?
Regarding the flooded area, while rummaging around I actually found in the sewers, the rats' lair and a gear stuck by a stone, thank you for this info ;)
I also found a creature hiding behind a wall that offers object swapping (really great :D)
When I find myself in the stone forest, an unknown entity seems to tell the player that he has acquired a new skill? Is this part of the elements not integrated into the game for the moment?
Going further I was able to discover a creature that seems to suffer from the same disease as Kristof. Above his head an eye seems to mean that we can interact with the area but nothing happens.
Anyway, your game is awesome!