Now then
AdventAnyx. It's time for some real feedback.
I played the game and I enjoyed it. I like the fetishes present, and I like the fact that it has a clear arc to it. So I wanted to give some thoughts here.
I think, and feedback from other people is all saying this, that you have fundamentally misunderstood your own merits as a creator. Weird thing to say. I know. But, the reason why is this:
The content with Ester is a lot better then the content with Gloria, but your intended focus is Gloria
This is clearly designed as a good, ol' fashion moral degeneration corruption game about breaking a bitchy boss. Gradually expanding tiers of extreme material. All that stuff. Only, I think her segments are really mediocre.
I can probably give you a whole essay on what I think you're doing wrong here, but if I had to boil it down it's that Gloria is too cartoonish to be properly detestable. Moral Degeneration and humiliation are drawn from the psychology of the charachter and if the character's psychology is very simplistic then your room for a long arc is weak.
I actually think your quote from above explains why.
"There's no "plot that is about MC and his girls and their goals", there's a set of kinks that I want to show and the "plot" is just to tie this shit together. "
See, a short moral corruption arc (the length of a hentai 20 pager) is pretty easy to do regardless of context. But, if you want to do a long slow drawn out moral degredation that really breaks down who a person is at a fundamental level, you have to be really intirested in and invested in the charachter as charachter. So all of that plot and high minded writing stuff becomes really needed, because you have to be doing hardcore charachter work.
But, then comes the weird part.
Ester Works.
Well not entirely. I actually think her introduction is kinda weak. But, it seems that accidentally, and against your own will, you stumbled on something that does work. And I can explain why.
Namely, Ester and the MC have chemistry.
As you said, the MC is an actual charachter with a personality and distinct styles of speach. One of the benefits of that it allows an H-game protaganist more room to interact and have dynamics with charachters. And Ester seems like someone who'd kind of like him. They have similair cultural touch stones, a partnership style mentality with each other, and a good rapport between them. But, also they have a good sexual chemistry in that it's implied that he sees her inner slut in a way that's repressed socially by her father and school position.
It is at times, and I am not kidding, slightly romantic. Or at the least it is remenscient of the kind of moments I've had in the past with girlfriends I felt chemistry with.
Maya is actually less good then Ester on this front, but benefits from lots of time just spent
talking to the MC. She also benefits a lot from having a clearer arc then Ester and from her interactions with Ester in general.
But, compare that to Gloria. Her rapport with the MC is very bland. They don't have a long personal history, outside of him dominating her or her yelling at him they don't have a lot to talk about. There's some hints at a competative of element of their dynamic, but it's sleight.
But, yeah. I think you might just have to face facts here. You did a really good job with Ester and Gloria is more "decent but not great".