Finally beat the fight, overall the game was pretty good albeit with a few glaring issues. Starting with the good though, the mechanics made to win the fight were really creative while not being incredibly obvious at first. I really like the idea of Susie's healing evolving into an overheal and using it alongside selecting Kris' actions to beat the fight. The dialogue as well felt really in character and grounded. A lot of fan games have the issue of taking reactions and dialogue to extremes, making them feel off but I didn't feel that at all in the game. Plus an exposition was also a nice bonus to it.
The art for both the sprites and attacks were also good, and for the most part was still visible and easy to keep track off when in the "bullet hell" segments. I will say the only gripe I'd bring up is in start of the final attack where slashes attack in a circular pattern. You used a red outline to highlight where the slashes would attack from and eventually get's to the point where they're covering the entire screen. Because the soul is also red and the highlights stay across the entire screen, the two blend into one another which makes it really difficult to keep track of and distinguish the two from one another.
While I did like the dialogue and the creativity of the mechanics introduced, I don't think I can say the same about the actual attacks. While some of the attacks, like the one's involving the black knives in different patterns, felt challenging but fair to dodge, a lot of the attacks involving the white stars bordered on frustrating. It felt like there were way too many projectiles at once, creating situations where it's almost impossible to dodge them and find a space where you can't get hit. The issue is most clear in the shield bash attack where the stars as shot upwards before raining down on from above the screen. There attack spawns so many of them that there were several times where they just formed a wall with no gaps that would lead to you taking a guaranteed hit. Also, on a more technical issue with the gameplay, the left and right input for moving around the menu options would sometimes just not register or be delayed. This isn't really a big deal on its own, but when you can get insta-killed for moving too far right on the menu then it becomes really frustrating. I had two separate occasions where inputs wouldn't properly register and I'd accidentally go too far to the right only to get killed for it.
All an all though, I still enjoyed playing through the fight start to finish. The core idea and mechanics are very strong, with all the issues I had being ones that could be resolved with small and easy tweaks (reducing the amount of white star projectiles spawned in some of the attacks or making the menu more precise for example) but overall really good stuff!