I personally like this game for the JOI. I've played a lot of porn games over the years, but this one is by far the most unique in terms of interactivity. For the most part JOI content will be in the form of pre-recorded video with an actress, instructing you what to do from start to end. The video has a set duration, and obviously you can't interact/input anything during, you just have to go with the flow. In this game you have interactivity. You can influence the instructions in various ways (asking for slower/faster intensity, signaling that you came early, etc). You also don't know when the session will end, or how it will end, adding to the suspense. Another big thing is that there are a lot of instructions, and they are ordered randomly, resulting in different sessions every time.
That's why this game (to me) is quite ahead of other JOI content in general. The reason why JOI appeals to me in the first place however... is actually kind of an odd one. Yes, one of the reasons is that being instructed and having someone else take control is hot, but the biggest reason is that it encourages healthy masturbation habits

. I find myself spending a lot less time on porn when the average session is only 15-20 minutes long, and I'm not indefinitely looking for the "perfect release". You get more grounded, focusing on the physical sensations rather than the mental ones. It also helps you find new/different form of stimulation instead of just repeating the same stroking motion over and over.
As for everything that is concerned with what happens outside a session, and the relationship between you and the succubus, I don't much care about that. I guess it's supposed to appeal in a BDSM-y way, and the concept follows very naturally when you are making a JOI game, but for me personally it's all about the instructions. Of course you want
some visual stimulation as well, so i appreciate having the succubus doing the instructing.