Here's what I'll say about this. The game is designed like a rogue-like, but the same level of thought has not gone into the narrative design.
1. The fact that the player character is always exactly the same is really poorly thought out and implemented here. What the dev is going for is some kind of blank slate type character. But, that just means they're an underwritten character. This is poorly thought out.
A FEMALE BLANK SLATE PROTAGONIST ONLY MAKES SENSE FOR A GAME TARGETED TO FEMALE-IDENTIFYING PEOPLE TO THE EXCLUSION OF OTHER DEMOGRAPHICS.
This should be obvious the more you think about it. To a male-identifying audience member playing a female-protaganist game, they don't identify with the protaganist sexually. Instead she's the main focal point of sexual content. That is, she should be desirable in of herself. This is true, btw, for games that target men and women both. In such a case, you just have to actually do the work of creating a female protagonist who is both easy to identify with but also erotic from an external standpoint.
The way the game is built right now, the main charachter IS the target of the sexual content, but she is much to boring to eke any eroticism out of.
2. Sex games are narrative games. This is because sex, as it exists in most video games, is a narrative (art and writing) reward for unrelated mechanics in most games. The way the player gets sex isn't through a core system, but basically a "reward" for surviving another round.
This is a problem because Roguelikes explicitly are not designed around persistent-relationships. Your charachter lives. They die. Life moves on. Yadda yadda. So you get this weird effect where you see these static NPCs, who are also slightly underdefined, go through the same motions of the same relationships over and over again.
3. This game appears to be a narrative game with the narrative mechanics of a roguelike. In a roguelike, the objective is to live, die, try again, etc. You're not building a dynamic with the cast in a single playthrough. But, the narrative and dynamics here appear to be aimed at building relationships with a core staff who are meant to help you reach an endgame.
The game is a story game with no story, so to speak.
The Consequence: A story game with no story. A relationships game with repeating impersonal relationships. A growth story about no one. A sex story with no erotic focus.
It is. In a word. An amateurishly clumsy and ill designed sex game.
How Would I Fix It: The answer I'd give might actually annoy a segment of the player base whose looking for completionist porn, but the ultimate effect would be good.
I would make three primary changes:
Change 1: I would intro a "Tag" system for the protagonist. She might start with "Cheery" or "Introverted" or some combination of 2-3 tags at start. If possible, I'd have that effect her visual appearance, but that's less important. Tags should have some kind of mechanical effect, but it should mostly result in conditional changes to the dialogue.
More tags can be gained as a course of play "Lesbian" or "Submisive" or "Whore" are all simple examples of persistent tags that can be added via play. Same too with things from the Arena like "Merciless" or "Crowd Pleaser".
The end result would be to distinctify the protaganist and make them more enjoyable on their own terms as a charachter....BUT also to lean into the game's Rogue-like nature and make the consequences of dying and starting new playthroughs more meaningful.
Change 2: I would shift the pre-existing ill-defined NPCs presently in the game. And replace them with a rotating cast of possible shop keepers. On this playthrough, you might get "Sasha" the hard drinking ex-slave as a trainer, but in another you might get "Maria" the Dominatrix, or "Andrea" the Futanari hired mercanary. Each would produce diffrent traits from interactions.
To keep workload low, most of the scenes would be written to fit all of them. But, diffrent trainers would have diffrent conditionals, making each scene about 70% common and 30% unique for each vendor.
The combination of tags and vendors would allow each iteration to present itself as a unique sexual experience.
Change 3: Strengthen the core narrative with a series of "Rank Up" events. In these, as she advances to the next level of enemy, an event fires where she is recognized as a higher level gladiatrix. These events should be mod-able both to traits and player choice, and should represent a core narrative spine to the game, that helps mark level of advancement. THey ultimatly lead the way for a final fight against a champion, or else allow for the introduction of side endings, like the protaganist choosing being the shop keeper's whore instead of a fighter.
However, the nature of the game is that they cannot be repetative. That is, any individual playthrough must have substantively diffrent consequences as a result of choices and tags.
Final Conclusion: Not a fraction of the time has been spent considering how to integrate sex relative to how to integrate game play. This has the sexual-narrative content of a (not very good) linear game, but the gameplay structure of a roguelike. You need to lean in and make a sex-narrative system that matches your gameplay, or you need to not do gameplay the way you are.