love it. the only things of note i have are... maybe a little prompt that says shift to run in game and not just on the page might be cool and... i don't think its intended but your decorations on the walls of the rooms still have hitboxes so your player sprite gets caught on them, leading to the occasional annoying death. I was playing the 64x version and it ran great! great job!
edit after continuing to play:
You might also benefit from having a sligtly move forgiving hit box on the sprite, if you are to assume that the light is on the floor, then a hit box that is only the bottom half of the player sprite might feel more natural and a little more forgiving.?
still, i went back to keep playing, so that should say a lot! :)