Super cool idea of taking the standard formular of a side scrolling platformer and mix it up with these lighting effects, it was a real "ahaa" moment when first encountering the all consuming shadows :D
I would suggest tweaking the character control because it is not something you would expect to be this hard as a "simple" platformer. Dont get me wrong, you can definitely speedrun this with enough practice but it would be way cooler to experience the mechanic with the lights itself instead of struggling with the controls. Nice short mini game :)