I love these type of games! The writing style and the books, as well as the illustrations inside were very neat. Props to you if you made those! I think some background music, victorian era style, could really add some flavour to the game. If the quality of the tinctures also matched the quality of the books and writing inside, then it would also really add to the immersive feeling. Agree that a tutorial is needed, and for me the trickiest was that putting a book back was quite hard in terms of controls. Overall, nice concept!!