Hey, great job on making this. There's a lot here!
The animations are sprites are beautiful. You did a great job with those. The combat feels pretty lackluster though. The small attack range and imprecise hit detection and lack of feedback make it hard to tell if you're hitting or doing damage. It gets a little easier when you get the invisibility/fire power. The combat felt out of place totally. I was able to skip all enemies except for the ones that you forced the player to fight. Combat for combat's sake is tough to pull off and I think this could have used more focus.
I got all the way to the janitor boss (certainly amusing) before giving up because I couldn't figure out to to reliably reload the cannon. Sometimes it seemed to work and other times not. Not to mention the soap was just hard to maneuver. A delightfully weird encounter though!
Congrats on finishing this, no matter the challenge. This is an accomplishment and you should be proud!