Something about this feels very old-school. Which makes it feel fresh, ironically.
I like the premise of someone who is clearly in way over her head, caught between her father and uncle. I think it'd be interesting to have the father/uncle start competing a bit to be her mentors, with each molding her into their image of what's best (uncle into more submissive and ultimately manipulative roles, father into more bold and potentially dominating or dangerous roles).
The sister relationship/romance seems unavoidable if you pursue the caring path. I think there should be a path for a too-nice, too-gullible girl taken advantage of, perhaps along with her sister. Or maybe the hate path with all blue/submissive responses is meant to be that route. I think some scoring to show personality changes from responses would be helpful, even if they don't affect actual gameplay.
I think the romance paths are far too fast. From intro to love in a screen. I assume, perhaps incorrectly, that the love interests are just manipulating the inexperienced protagonist, but if so, I think this should be expressed more clearly, e.g., having them dismiss her after they've got what they want (politely enough that she doesn't catch on). Or, three alternative approaches that would allow actual romance in an immersive way:
- have her start already in a relationship (with whom, selectable as a setting?)
- only take the romances as far as having something happen for her to see them in a new light, then stop there (at least as of release 1)
- they use her, then feel bad and strike up a conversation, and start to develop real feelings.
The actress you've chosen for static graphics is good. I agree that the gifs are slightly immersion-breaking, mostly because it's obviously commercial porn. With all the amateur stuff out there, I'm surprised how often the "real sex" tag leads to over-the-top commercial stuff. An option would be a more lo-fi filter approach like Playing Judas/etc. Is there a way to source -- even commission -- some amateur stuff? Even just for softcore graphics.
I'll be interested to see if you continue this, it doesn't seem like many original games last too long. I'd suggest writing out the canon story to completion before taking on too many patrons or a publishing schedule. Then all you have to do is produce some side options for each release. Alternatively, consider taking on some additional writers, with yourself in a core/editing role.