Oh, yes you already had the difficulties, sounds like a good idea to have ez mode for people like me :)
But with easiest mode it was very beatable, without dying. So I guess it really is not a problem!
Interesting with the highscore, did you push score to your own server? Would have been fun if itch could provide a tiny bit of storage for that kind of stuff!
One more thing I came to think of. It would have been nice with some sort of hurt animation or effect on the boss. First time I was not sure if I killed the boss or the other way around!
Really cool game, once again.