Having played it, here's my thoughts so far in no particular order.
I like that the guy is giving some obviously horseshit "no no it's
her fault I'm kidnapping her, I am blameless, if anybody is the victim it's me" justification on this one. He can lie to himself about what a shitbag he's being, but not to us.
The way the plot starts off, and the cop coming to your door and asking about her, means that making the girl your sister or some other close relative would require doing some rewrites, it's not as simple as the old "landlady/mother" or "roommate/sister" swap. I do still want that, of course, because that's where my tastes run, but this is just me acknowledging that it's a bit more work than a search and replace.
Once you've got her, hopefully there will be some options for extra, shall we say, "pharmaceutical compliance." Which is a five dollar way of saying "I want ways to drug her." Something to make her compliant, something to make her quiet, something to make her horny, and if you're willing to go that way, something to make her fertile. Why just keep her in your basement as a sex toy when you can make her a breeding slave? This does then get into game balance concerns, but I tend to rate "is it balanced" far below "is it hot" for this kind of thing. Maybe "you can use one kind of drug per day," and don't worry about where they came from.
On the grammar front, I will point out that punctuation usually goes
inside the quotation marks, so that's something for the next pass, I guess.
Because it's just a demo, I understand the need for an abrupt end, but I'm hoping that for the full game, you have a chance to see failure coming and avoid it, rather than "oh you took this one dialogue choice, well now you lose, game over." Options that wind up in the same place but worse are also not ideal, such as when she offers to use her mouth or hands, and your choices basically come down to "fuck her anyway" and "fuck her anyway and also get +3 Noise."
Overall, however, I have to say I like it so far. It has a nice, focused premise, so that should help keep scope creep under control. And yes, I am aware of the irony of saying that after asking for an incest option and a drugging system. I said "under control," not "eliminated."