Not bad in my opinion. A bit spooky, but not so scary that it would make my heart jump out of my chest and slap me for what I just did. I don't know if anyone encountered the same issues as I did, but the SCP 6781.exe file wouldn't allow me to get past the menu so I tried the Project mine.exe instead. I have Windows 10 so I don't know what happened there. I reached the end of the mine and fell outside the map into infinity I suppose, but I'm sure that it probably wasn't supposed to happen in the actual file I was supposed to open should it have been available. There is potential for this to expand a bit more. Definitely room for more details here; one suggestion is add twists and turns to the path that makes the gamer feel like they are going in circles, jumpscare and then back onto a normal pathway out of the loop. IDK
Lots of different things that you can do to improve on this, but it's still pretty good.