I like the sound design. The visuals are also intriguing but the grayish tint is a little strong and makes everything feel washed out. A little more colour would go a along way.
The Parkour bit was very frustrating. After about half an hour of trying and failing the lava parkour, I decided to give up. I've read that you are planning to nerf the parkour, so I'll check the game out again once you've finished it.
I'd recommend changing the player collision shape from a bean-shape to a cylinder-shape (if it is a bean shape) as I believe that is the reason I often got stuck on cliff edges.
Edit: I played through your game after your last update now. The Lava part took me a good 10 times now and I just barely managed to escape before the lava got to me. Especially the concluding section of parkour with the lava pit and minecarts was a source of many deaths.
While I liked the idea of the next chapter, it was near impossible to differentiate the "evil light" from the dark background. Often I would walk into it, just barely perceiving the sound and instantly dying. Being reset to the very start of this chapter everytime it got me was another source of frustration. In total it took me about an hour to complete your game.
As I said before, I liked the sound design and music, but the gameplay was much too punishing for my taste.
Please do not be afraid to make your next game more forgiving.