The level of polish that's gone into this is impressive, I love the rainy windows and the different flourishes and decals on the walls and props that break up the space. The subtle sway of the camera, the creepy portraits, and the general the cosmic horror vibes. Reminds me of the mansion in Eternal Darkness. Very atmospheric and evocative, and kind of spooky.
I did have some trouble finding the switch on the fireplace, it was a bit hard to see and I had to hunt quite a bit to get it, and the tutorial was a bit dry but other than that it was an enjoyable experience.
The ending was pretty grim, but I think it fits the madness motif that you've got going on throughout the rest of the story.
Great work!