Regarding puzzles:
- When you need to type the code into doors - I instantly guessed the mushroom color since there is not that many with 6 letters in them. But with the other door - I just couldn't find the right book because I couldn't figure out that piece of wood peeking from below is actually an edge of a bookshelf and is completely interactable. Even with guides telling me what exact room the book was - I still was lost for some time. It just was visually not clear. Also it was a little too on the nose that most books except for the one which will help you with puzzles are described with bland texts in dismissive tone. You don't even need to look that much - this puzzle pretty much solves itself.
- Puzzle with the dead and rubber fish is a tricky one since their position is more ambiguous than it seems. Also I desperately tried to pick up stuffed fish but suddenly it was not good enough for the scene.
- Almost every act requires a girl doll and I spend some time interacting with the girl doll in the room with mushroom houses. Turns out it is not the right girl doll I need and I can't pick it up until I'm gonna need it. But I have no idea about it. So every Act I had to visit that room and interact with the doll just to see if it's the one I need now. Actually in one of the acts I had two girl dolls in my inventory and neither were of any use for that same act. You better barrier away the items you don't really need behind some puzzles or whatever would work.
Bloodsucking mechanics are just not really clear and you don't even realize that there is some time limit unless you will really look for it. I blindly poked every corner of the mansion for some good time and still got like half of my thirst meter full. If some death traps would inflict thirst increase instead of instant game over, and it was evidently shown - maybe then players would realize that they have some life resource. And maybe if characters mentioned that their time in other dimension is fairly limited - then that mechanic would make some sense to the player. Right now it serves more like a gimmick that nobody will notice due to factors mentioned above.
On text: even if your game is a Visual Novel - over exposition is still a poison to the flow. It is a good rule of thumb to cut about 10-15% of the text with every draft. Spreading the narration evenly is good for the pacing too. You need to keep things short to the point even with VN's. Switching from text dumps to some action and puzzle solving in even intervals is necessary to prevent players from losing the track of plot. Texts in games are like cholesterol in veins - it is good in small regular doses but spikes of it results in severe clotting.