Finally had time to give this a go. Some minor stuff first
1) Right click to skip the 2min startup cutscene is unusal. Maybe think about other key presses as well
2) When you go from INSIDE to OUTSIDE (see pics) it doesn't look right. All other inside/outside transitions look fine, but for this one the inside you see on the outside is difference from the inside you see on the inside

3) I found it VERY easy to miss some doors (see pic)
4) This bookcase (see pic) said "There is space here" or something, so I dropped a book. I then couldn't pic the book up.
5) I had the molotov equipped and equipped the axe. The molotov was then gone. Unlike the axe when I equipped the molotov the inventory space became free.
I wanted to like it. The place is so big and kind hard to tell apart that I ended up just wandering and wandering. I wondered as I wandered if I'd just missed something important. Like the board I walked past several times, or one of those blooming doorways, or a secret bookcase that looks just like every other bookcase.
So in the end I found a gazzzzzilllionnnn notes, a blue crystal, lit a fireplace (only one not sure how), saw a gun behind a locked door, saw a key in some place I could find, met a bloke who wanted me to get the gun, and got killed instantly by some red crawling skeleton, but never really felt like I was getting anywhere.
Did like the footsteps and invisible monster though

So my general complaint is you can wander everywhere, but there aren't that many puzzles (that I could find anyway. I guess I did one or two), so it's hard to find any focus. There's not really a sense of progression. That and it's easy to miss some of the objects.