Very well put together and also a good example of how modernized formats can help a wider audience to engage with older works. While I don't particularly care for this style of art, it is well done and kudos to the care and detail done with the characters' expressions. And the music was surprisingly mood setting while also remaining un-intrusive which works well for different reading paces.
It was interesting playing this for me because I had actually already ready Le Fanu's novella (however I have not read In a Glass Darkly), so this was not my first foray into the literature. It really struck me how close to the original text the visual novel was, it is almost a 1 for 1 alternative to reading it in traditional format. Most of the differences I noted were small and innocuous (such as removing "fat" for the description for Madame or changing Carmilla's hair highlights from gold to violet to better match character portraits) to notable improvements (removing the description that the ugly demonic woman in the carriage as being "black", removing the racism in that passage -- thank you for doing that, greatly appreciated). There is one exception that struck me odd though, and that was the complete omission of the final chapter (Chapter 16 in the original, though this format combined most of the chapters together) with Baron Vordenburg's explanation. It's pretty crucial to the narrative as it is the expositional wrap-up of the whole novella, so it struck me odd that it was almost entirely omitted (though subtly referenced in the final bits). Also struck me odd as Vordenburg had almost no character portrait or any focus at all in this version. If I were to be cynical, I suspect it may have to do with the fact that he and the final chapter does not entirely line up with the interpretation presented in this edition, but it could also simply be development time and funding ran short.
This interpretation of Carmilla I found very interesting, well researched, and thoughtfully contextualized. That said...I personally don't find it be the best fitting interpretation, interesting as it is. It's a great addition to the original text and other interpretations and research, but alone I'm not entirely sure. My opinion might change after I've read In a Glass Darkly though, as I haven't read Carmilla within the context of the entire anthology.
Oh and there seems to be a slight miswording in the Notes for Camera Obscura. It states "the Camera Obscura implies objectivity of human sensual perception and therefore, by extension, scientific objectivity". However, "sensual" refers specifically to the senses in regard to the carnal or sexual. I believe "sensuous" was the intended word here, "sensuous" referring to something pertaining to the senses rather than the mind or intellect.