I really like this game! It is a very clever idea thematically! And it has some very good puzzles! Great! What I liked was that, unlike most "Only one light" game, you didn't just use the light as way to look in the dark, the light is the core of the game's mechanics, which is really clever. But, what I didn't like though was the player's movement. It was a bit clunky at times; sometimes I would fall off the edge for a reason out of my control. I also didn't like the camera controller as much, even though you had some cool ideas (like to hide the wall when inside a cave), but in general 'sometimes', the camera would be too far in one direction, meaning I couldn't see either where I was going or what was ahead of me for the puzzles. Apart from these few polishing problems, this game was great! Very original and coherent to the theme! Well done!
I made a game very close to yours under the theme "Only one light", where the light isn't just use to see but also as the core mechanic. Would love if you could check mine out too! Or not, no pressure ;)