Good puzzle! Good atmosphere.
Overall, I felt that there was not much explanation. The first floor just ended abruptly as a result of random manipulation, so it took me a while to figure out what happened.
On floor 9, I noticed for the first time that I could place panels directly on the spider, but I eventually gave up because the spider would be hidden by the panels and every time I replaced the panel I placed on the flame switch, everything would reset. I was able to capture all the floors up to that point, including the treasure chests. It was fun!