Interesting review. I might give the game a try. Conceptually, I really like Visual Novels. Games will often try to balance gameplay with story, or in some cases, story with gameplay. There are many variations to that structure, and in many cases, some of the greatest video games focus exclusively on gameplay. What intrigues me about Visual Novels is that they are on the opposite side of that spectrum, and I do think there's a lot of potential to be explored in that genre, but unfortunately you don't see many mainstream titles takes advantage of it.
I've played a few visual novels, like the Phoenix Wright games, although the format of a VN is typically more like Nine Hours, Nine Persons, Nine Doors, which I also own. A few people on here already mentioned "Digital: A Love Story" and "Don't Take it Personally, Babe, It just Ain't Your Story", but I didn't particularly like either of those. I also played a few by Sakevisual, and they were okay. I suppose my problem with VNs are that so many of them focus on romance, and I would be more interested in seeing them explore other themes.
if you would like to look into another highly-regarded hentai VN, you should read Leigh Alexander's post on Kana: Little Sister. It's on another taboo subject, and your blog does overlap a lot with hers.