I want to review this as fairly as I can, as I think the base game has an interesting enough foundation and I would like to see it improve.
I think the biggest thing about it that I can critique is how it opens. When you boot it up initially, it basically has you go through lists and lists of fetishes, toys you have, specific phrases, exact settings for sliders, it's a LOT. It's honestly overwhelming, and I think the best way to handle this would have a default preset to help you get into the game faster. In fact, I think having general presets would help a LOT in speeding up people's time between opening the game and playing it. It should encourage you to alter them as you want, but as it is now? It's just so much. I think the best ideal "starter" preset is to assume the user has no toys and let them pick between different types of personality layouts, like a "Yandere", "Tsundere", "Sadistic", etc.
The next thing I would love to see get a major overhaul is appearance options. Specifically, body types/body sliders. I know I'm asking for a lot by saying that but the whole draw of this game is that she's supposed to be your ideal succubus. So letting me make one that is plus sized, or muscular, 7' or 4', I think stuff like that adds a lot to the game, and would absolutely keep my attention on it longer. With that also said, in time I think it would be cool if certain appearance options became sex options. IE: I know there is a dick tail in the game, but a version of a dick tail without balls and was much longer/prehensile that she could fuck you with would be something I would love to see. It's a huge request, i know, but I will still ask for it in hopes that maybe one day we could see something like it.
Speaking of gameplay, it felt very difficult for me to adjust the settings in a way that made the succubus act how I wanted her to. I would pick a ton of different submissive options and it felt like all she would ever do is edging mini games over and over. That and counting. The sessions also felt way too long, even when I set them to the lowest amount of time. I get a lot of this game is sexual frustration, but after 15 minutes I felt more bored than desperate.
I hope the dev(s) continue working on this, I think they have something really amazing here and I hope that what I said can help them in making the game better.