This was really fun! I love watching the little racetrack to see who's gonna go next. My only critiques would be that the pace is fairly slow, each battle simply takes a while. The fight against the 3 worms in the exit was fairly quick though, which was nice to have a break from the tedium. Also, in one playthough I got softlocked-ish against the Sphincter because we both just kept defending, and neither of us could simply do enough damage to move the fight forwards at all. Also, some quality of life things like a numeric amount for your health and defense, as well as seeing which buffs are currently active would do a lot.
Overall, good job, the art was good and I liked the simple turn-based combat!