I think the idea of a playable female character who is the one taking advantage of defeated foes is an interesting premise that isn't explored very often. The only other (English) game of this theme that I can think of within the last few years is Femtality!. While I'd prefer the protagonist to be a male who is exploited upon defeat, it's still a female character doing the dominating nonetheless. I don't know if you plan to allow the female character to be raped upon defeat but you'll likely have a lot of people making that suggestion as that's what they've come to expect whenever they see a female character in a game where she can get beaten up. Personally, I think the focus should be more on the femdom aspect with any 'male domination' coming much later. There's plenty of games as it is where the male can have his way with the female.
Otherwise, I think the controls are good and responsive and simple enough unlike other 2D beat 'em ups where they add many different keybinds to familiarize yourself with. It's rather simple to just have a dodge, light attack, and heavy attack and this is a good thing. At most, perhaps you could be a bit more generous with the invulnerability frames after dodging.
I played it on easy mode (because it's a porn game and I want to see the porn without any struggle) but still felt like the opponent you fight did too much damage and had too much health. I still won on my first attempt but as the game progresses, you're going to have a lot of people complaining that:
A) Fights take too long and,
B) Enemy does too much damage.
Easy mode should exist as a difficulty setting for people who don't really want to grind or be too challenged. I tried both difficulty modes between easy and normal and there doesn't seem to be much of a difference, in fact it says that dodging isn't required on easy mode but it still actually was. If I wasn't dodging I would have lost because it doesn't seem like your attacks properly interrupt the opponent, so it's not easy to chain or combo.
I assume by "souls-like" you intend to implement an RPG system where you can upgrade certain statistics like the stamina (which also depletes way too quickly in its current version), health, attack damage, etc. Assuming that you can balance this XP system properly, that might help but in general, I think the base stamina bar should be bigger or actions should require a bit less stamina usage. This would allow people to better combo their attacks and defeat their opponents quicker. As a caveat, maybe you can make stamina regenerate slightly slower, where players can workaround that by just retreating until it recovers.
What people aren't going to really ask for is some sort of in-depth combat system à la Street Fighter, they just want to fight and see the sex so you'll need to find that perfect balance where the sex is not too tedious to accomplish. Reworking easy mode is probably the best way to do that. Perhaps damage received can remain the same but the opponent has less HP compared to the normal setting?
I also think the idea of a 1v1 arena could be pretty cool. Other games have done this as an idea, like Under The Witch. What a lot of these 2D side-scroller games have is a bombardment of enemies and then it just shows how repetitive a lot of it is when you start to see the same enemies just chasing you around the map. Every map just having one opponent who is somewhat of a "boss" could be cool because then it'd allow us to really focus on the combat and the sexual aspect of the game.
Also, don't forget that cunnilingus is a thing. A lot of these femdom games have too much of a focus on male pleasure.
Either way, good luck. I'll check back for future updates.