One of the best demos I've played in a while. Everything from the sound design to the atmosphere to the monsters themselves. I was getting SCP VIBES the whole way through. I believe with the right amount of work put in, this game could rival SCP containment breach.
I was a HUGE fan of the respawn cutscene thing too, extremely cool.
Can't wait for the full game.
I made a video on your game if you're interested :)