I've played up to the City so far and I have to say this game is awesome! I haven't played an adventure RPG game quite like this but it's really unique, funny, and hard to put down! It's like a Zelda game meets Chrono Trigger, but it's tone and pace make it way more than that. Kudos to you!
My suggestions so far would be to add more map transitions to give the game a bit more of a polished feel and to consider making the timed hit window a tiny bit more forgiving (at least the window to get a Good)/make the red exclamation a little more react-able.
Also some areas where the screen faded to black (I remember it happening once after defeating the Spider Queen) stayed black for a really long time and made me worry the game crashed so I'd double-check that lol
Another concern I had was getting lost after I defeated the boss of Snail Cave and wanted to backtrack to do a final sweep over paths I missed. I didn't really get lost otherwise which is a great feat for a game like this, but I have some ideas for making it even harder for a player to get lost.
- You could add a way to mark the map like in BOTW. This would make it easier for players to chart their own path and set their own priorities through the dungeons.
- You could add more conspicuous landmarks to rooms, especially ones with multiple exits, so it's a bit easier to get your bearings.
- You could even do something like Super Metroid where each large area has regions that differ by tileset/tileset palette. For example, the Snail-dominated part of Snail Caves might be its normal color, but beyond the spider door it changes to a more dark and spooky palette.
Feel free to use or not use my ideas of course! I just had a lot of fun and love reading into game design. :) Please keep making games and updating this one! I'm excited to see what you release next!