My initial thoughts are that I absolutely love the concept! Really cool idea to play with object permanence (or lack thereof) as a game mechanic. I got as far as level 11, and at that point found that my reflexes just aren't good enough to handle the fast moving platform - but I'll give it another go later to see if I can get past it.

I thought it was a very interesting idea, I love games that experiment with new things and game mechanics, but it quickly went from being a fun idea to mostly frustrating, especially since you can't change the controls. Using the mouse and stretching the other hands fingers to control arrow keys and then jump with space is not really that different from playing a piano/keyboard piece that your hands are nearly or just a little too small for. I tested this on a trackpad, but I don't see an actual mouse making that big of a difference, while the possibility to change the controls actually might make a big difference.

Are the exits meant to exist even in the dark? I jumped into the unlit exit on level 7 before I realized the last light was switchable, and I still exited. I couldn't see it.

Edit: very cool game though. I enjoyed it!

This is neat and really enjoying it! Though admittedly stuck at level 14 and not sure if I am missing a fundamental mechanic to solve this one or if I'm just really dumb.

[Edit] I figured it out and it was because I was fundamentally misunderstanding some throwing physics.