I was sure I've seen you here in the past. Hell, I thought this game was part of the inspiration for your own.
Anyway if you start from scratch the amount of content is pretty generous: there are a total of 6 floors in the game, all with a subplot of increasing lenght and quality during which you'll get to know the villainess (and usually get enslaved). Also the last 2 floors are doubled.
Additionally there's some bonus content in the form of challenges, festivity stuff and so on.
My save file has give or take 30 hours in it, but I've completed every single little thing... and I do like to take things slowly.
Kinks wise the game has more or less everything femdom related, with more extreme stuff (gore and scat) being very rare and skippable. Only thing I can think of that's not in the game yet is an ashtray scene, but it should come in a few updates. Also vore.