I'll start off by saying that the game looks great and runs very well, I had zero graphical or performance issues while playing. The atmosphere of the game is somewhat tense, and while the mannequins can at times be very creepy, there were only a few moments where I found myself actually scared. Story wise I believe you have a solid foundation here, there's plenty of room left to expand upon things and really drive home the "murder mystery" type story going on here.
I encountered a few minor bugs, one being with an enemies head poking through a door, allowing me to shoot it easily, and two being with the security room where you have to deactivate the power (I'm assuming that's what you're doing), the prompt to interact with the system wouldn't appear unless I stood in a very specific position.
All in all I think this a solid demo, and hopefully a decent taste of what's to come.
I hope you don't mind but I made a short let's play of my time with the game.
Cheers and best wishes,