I do plan on adding sfx/music in the future, but it's not something planned for 0.1 as I'd rather eventually commission music for the game and that's not something I can do quite yet. And there are no planned futa characters, but one of the students, Frankie, is trans. And yes, you will meet parents in the game (though only one appears in this demo). Whether or not they'll become part of the harem or simply one-offs remains to be seen; I suppose that's something I'd like to gather feedback for. Thanks for playing and for the questions!
Hope this helped.