Okay as a concept demo it is 3/5. There is a slight issue with ending the stage... I put a strategy together, and promptly cleared the 15 minute mark. (Holocure taught me well.) Yet, there was no hint that the progression had stopped. Anything, doubling the sizes of the enemy sprites, progressively speeding up the enemies, making the health bar shrink past a point. Or a little trophy or heart in either corner could have signed the stage was finished. (Also have an auto-mash selection that scales with the PC's level to avoid carpel tunnel)
Aside from that I jest when saying that if it were foreplay only. Surely there was be actual game overs (penetration, orgasm scenes) added later. This is a creative use of AI and I approve of the implementation as long as there is a clear effort in the animations. Finally my last comment for what may fit into things.
More fantasy. Maids, imps, (fallen) angel wings/halos, dragon horns, armored maidens princesses, and so on. Take inspiration from the Monster Girl Encyclopedia. And take cues from the games that brought in this genre.
Edit: Minor QoL recommendation, have XP items merge so there's less visual clutter.