I like the atmosphere a lot, but I don't agree with the design choice of letting the player fall into the pit again and don't have a way back
I played the game before reading anything and it was a kinda annoying experience (even figuring out how to show the cursor).
Ok, so I replayed your game:
The first and second challenges were all balanced, but then I discovered that you have to do an unnecessarily annoying jump (the first one) to continue the game. Then I got to the top and got killed.
I'd say maybe remove the arrows if a challenge is already completed, or maybe give the player a way out if they fall down there again. Not all people are going to continue playing if they are annoyed by something that's not their fault.
Bugs:
I only found one bug, you can complete the yellow room if you only collect the top relic
Overall I liked the visuals