I understand your frustration. With such a tight deadline, I didn't have time to test the final boss on other emulators or on the real console; I only tested it on Mesen. After launching the game, a few minutes before the jam finish, I went to test it on the real console and had a nasty surprise: a visual effect using OPT wasn't displaying correctly. I was desperate and tried to fix it as quickly as possible, but it was taking too much time, so to calm down, I simply removed the effect and released version 1.1 as soon as possible, and then I was at peace. :')
Making a game under a deadline was a very different experience, including the ROM size limit. I'd never been so concerned about ROM space and graphics compression. But I feel good about using the SNES's large RAM for something.
Congratulations for your game, I loved it!