I like the non-harem idea, forces you to actually pursue one girl and making it realistic. What i would want to know is will there be any consequences to doing so or not? Like a surprise pregnancy or something idk or the girls finding out you're cheating. My main fetish is like having family, getting a girl pregnant and spending your life with her, which a lot of games don't do.
As I've answered in some posts before, pregnancy won't be some real part of the story. Do I wish to have it in some characters endings? Kinda, yeah. But besides such endings, no.
Cheating, maybe. Naturally here I can't say much, especially as I don't have myself everything set in stone yet, but you might anger some if you really go for everyone constantly.