Hey this was really fun! The use of light was really interesting, and the later levels were pretty hard (having to remember where the platforms were). Felt good to finally get it!
Also really loved that your start menu had little playground areas but I couldn't get to the end of some of them... are there secrets there that are worth more attempts?
The character controller felt really smooth and I'm curious how you did it (especially the jump). Felt great.
For feedback, I'd say that there were some points where I was "walking" in darkness but really I was just pressed up against the wall. There were some points of the game that you do have to just hold down right and make it through the darkness after 3-4 seconds, so I did that pointlessly a few times where I wasn't on the right path.
Having a tiny character outline or some indication that you aren't actually moving would make those parts less frustrating.
With that, great job! Especially in 6 days.