i dig it, great atmoshpere and visuals and the movement system feels good all around once you take some time to learn it.
and now i will rant about game design, this stuff might be subjective to what i like, so take it more like a suggestion instead of critisism.
i like the difficulty and "arcade" lives system once i got used to the controls and figured the game has a very forgiving coyote jump and its all good for a demo, but id consider this like "middle of the game" difficult. you might wanna have some easy sections to begin with simply to get the player used to general movement (introduce coyote jumping, neutral jumping off wall), so it doesnt feel like you are thrown into a hard section that you need to trial and error to learn especially considering youre using a lives system that throws you back to the start of the game. when you make a game and playtest it yourself, its hard to get an idea how difficult something really is for a blind player.
for a short demo i think the "arcade mode" is a fair challenge cuz the games very short but id personally maybe make it a hard mode, and the regular difficulty of the game basically gives you infinite lives to restart from latest checkpoint.
1 last gripe, spike hitboxes. generally i felt the spikes were fair and i didnt have an issue with it but a specific spot in the last room before "snakes room" you got some spikes at the top of the wall you need to walljump off of but you can die by touching the side of the spikes. that one didnt feel good imo.
aight thats it, i would love to see a full game one day, good luck on the project!