Very interesting game, it took me a lot of time to figure out the real signification of those symbols, but once i did, it still was a real challenge to solve all the problems. Since they are pretty hard to solve, the rewards gets bigger when you succeed.
Nevertheless, maybe you could work on a more dynamic end, since this one is pretty, but too ... passive. Maybe put a text, something that makes us understand what this cavern is about, a funny ending, i don't know ...
I would like to write a walkthrough of this game, do you mind ?