I really enjoyed this demo. I love VN concepts that involve obsessive characters. One of my favorite aspects of this was the use of sound. The moment where the player is in the dark but you can hear Dmitri breathing and whispering is a startling moment and honestly spooked me.
My only critique would be that the conversations feel one-sided, and I suppose that's probably the intent. But the player spends a lot of time in their head and I feel like some of that time could be spent having a more engaging back and forth with Dmitri. I realize, however, that this is a demo and that the final version will likely be different.
All in all, this was an enjoyable experience! :)