This Visual Novel was absolutely incredible! Certainly far better than the old stuff like My Stepsister Hitomi, and a number of other ones. Maybe a bit better than even Monster Girl Quest. (That one was a Hell of a doozy!)
It's amazing that you used 3d modeling to transition your creativity and really bring the characters to life. Even the legendary Stabby Stabby had a lot (and I mean A LOT!) of presence in this game. Actually, is this even a game? It's practically a demon in its own right! lol
Although there are a few points I've been only slightly disappointed at due to not having the necessary choices available, it's also understandable from a young adult's perspective to not completely prepare and all that.
So, besides what I found both incredible about the game as well my own opinion and insight for it, I just wanted to say that I have started my own Doujinshi for this, a sort of rewrite for it were things different from the MC's past (get this: I actually named the MC Satan for one playthrough. No "All hail Satan" moment, but still, pretty funny!), mainly if there were a Deus Ex Machina involved with one of my own personal characters that I usually write about in my books.
Anyways, what I wanted to ask you and your team directly about, Caribdis, is if you would like to at least read the book I'm making (Absolutely free, moreso considering it's your own work and property) and if you could give me your thoughts and opinions on it at a much later date. Mind you, I'm still working on it, but will be willing to give it to you after its completion.
Regardless, excellent work, chap, and please keep striving to do better than you did yesterday! Just like the MC, YOU CAN DO IT! (Little Nicky reference)
P.S. Really loving all the references, and maybe I should pay Ulric a visit and get my own Angel's breath for the road.