I'd like to have an estimate in numbers because I'm not sure if I should initially provide a short demo with only a small portion of the planned content (to evaluate the reception of the people) or whether I should wait until I have included all the planned fetishes (delaying the game drastically).
I can't say that it's applied to every titles, but based on my experience from playing a few (linear style) titles which still in early stages (first/second build), in average it took me around 20-30 minutes to finish with my reading speed, which kinda difficult to described with exact number
The display of (planned) fetishes/genre is surely important, but once again I would think it would be better to focus on the plot/premise explanation and the display of main characters/pair (M/F, M/M, F/F) at first while waiting for the feedback from the player
So u could immediately put the "market's demand" into consideration for developing ur game to be more (potentially) better and even popular
I'm not an expert and I dunno about others, but from my experience for playing around 80 titles, I had to drop some of them in the very beginning due to their lack of appealing in the premise
Some are not clearly explained, some are too much cliche/drama, some are pure bad
I could stand a just-so-so model and animation, but I can't stand a boring premise (it's a VN anyway, if I only looking for the sexual content, I might prefer to download an AV instead, lol)
This is my personal opinion btw, sorry for the roundabout reply
Wish u a good luck for the development of ur game, mate