After having read/play a good chunk into the game(though, not all there is as of latest update) I can say that I really like it, like always on this site, but especially with this kind of games however, is very important to pay attention to the tags and genres, those have a reason to be there.
Back to the VN though, overall has quality and a lot of content, one of the best traits for me is definitely the art, while not the most 'clean', has personality and is actually proper so to speak, the style is also nice, haven't seen it on a lot of recent NSFW games, beyond that though, the game itself is entertaining, in particular I liked the characters, Cecille in particular, the fact that she's wasn't just a 'Flawless Main Heroine', but actually had some sly side to her, even on the early stages, as she herself, not 'warped' by a external factor, that bit of flavor to her was definitely a nice addition, that's present, albeit in different ways to other characters, make it easy to get more invested on their scenes, be it just dialogue or sex. Other thing are the few mini-games around the game, while they can get a little tiresome at times, they don't fault at being disconnected from the main story, so it's just an addition, more often nice than not.
Some less favorable points however, could be how the game can suffer from some bugs not much of a big deal, other more subjective for me is Erin, previously I praised how most Characters are nice to interact for the little extra flavor they get, with that I don't mean just in a favorable light, some being more unsavory is also a thumb up for me, but Erin, I feel like he's too simple in comparison to the others(might change in some of the stuff I haven't reached, but I dobut it, since he's more of a side quest), like just there to be the fool, feel like it could have been more to it but uh. The story is also needless to say, very centered, since is a clear goal, so not a ton of freedom, which I don't think is necessarily a flaw, since from the title you get the idea of what's all about, still, something to have in mind, most things are 'small scale'
Other thing that I appreciate, is that Mars is not a nameable MC, no shade for games in which the MC doesn't have one though, I enjoy some of that, but here I think it was the proper call make the MC a more defined character, his different options being mostly logical for someone like him to have, he's obviously a malicious man, not a good person at all, pretty much a Villain Lead, still, not a Super Monstrous one, his bond with Vi, plus the fact that his Goal is a Greater One like change the game for his species, not saying that Demons in the game are good or something, they are wicked, but having their role as species write in stone by a Greater Power such as the Goddess of that world, like a sort of Cosmic Irony definitely sucks hard and working to change that definitely add to them, a noble cause?, not really, but at least a proper motive is good to have in opposition to just 'Mess over the Hero party and cuck him'. To finish, while Mars's a bit plain-looking, I really like that his design leans more to an attractive man rather than an ugly Doe, which seems to be the main two options in Male-lead NTR stuff, that's personal preference though.