The game has a very good concept to it that would definitely be a great foundation for a longer experience with more scope.
The use of the light mechanic was fairly engaging, but there definitely could of been more atmospheric and horror oriented uses of the play on dark and light instead of it almost purely being tied to the danger and puzzle elements of the game. The creatures were neat although seeing the table woman so clearly in the light spoiled the contrast of her being dangerous in the dark, since you can clearly see that she isn't furniture when the lights are on.
The audio and story were generally the weakest parts of the game. It would of been more impactful if the ambient rumble in the background only played when the lights are off. There wasn't really any story to it and what little dialogue was there didn't make any sense. Room 202 seemed especially unforgiving and required a fair amount of trial and error to get through.
The ending was awkward as you can clearly see the tall women walking past the protagonist before the lights go off and even when they do the game still is clearly running. There also doesn't seem to be a way to actually close the game afterwards.
This is great as a demo slash proof of concept and would certainly be intriguing to see it expanded into a longer game with a story, using the dark and light for more atmospheric and horror oriented events instead of just dangers and having more cohesive audio overall.
You should also try adding more tags to the game and making it browser playable if possible, as both those things will significantly increase the amount of plays it gets.