I was super impressed by this! I missed that this was a demo and was so sad to find that out by getting hit by the "thanks for playing our demo!" screen because of how invested I was.

The atmosphere of the game was easily its strongest part for me.  Particularly in the beginning part of the caves (before you actually open the gate) where I was wandering in the dark caves, hearing rumbles of the monster in the distance made me paranoid wondering if anything would pop out of the dark at me. The jumpscare + chase at the end really got me, there was enough time between the encounters that I had gotten comfortable just wandering around freely again, even with all of the notes explaining how it'd be obvious that I wasn't alone down in these mines.

Some points for improvement: some of the controls felt a little clunky to me, specifically the few moments where I had to crouch jump into small areas like the mines or air vents and opening doors. I don't think I would have been able to do either of these things gracefully if I were being chased by a monster, for example. Also since the monster doesn't insta-kill you, having the red tint last for the entire rest of the demo was a little bit annoying to deal with.

All in all, I had a really fun time with this game, and I'm very much looking forward to seeing the final result! Great job!