More on music (music has become a big passion for me during the last two years), I think checking out DDRKirby might be a good idea. They have a 9-bit style, so it's pretty close to what you make, but with just a bit more modern instrumentation and use of FX. The sort of fit in with how chiptune sounds in my head. They have full on videos of when they make the songs, and they are super fast, most songs are done in an hour or a bit more.
Cape! I just thought it's funny it works so well, the cape is like the 2d equivalent of cloth and hair simulations, which generally work pretty meh. So it's cool it's working and that you might continue with it!
And about falling through the map, I guess that is more of a problem with löve than anything you can really deal with, if you used their system. I'm really happy they have it though, physics (mainly collision detection and handling) isn't something I think is fun to write, so it's a big plus. Will have to figure out how to actually use it first though. It's a nice change of pace compared to godot and unity where they are so complex it's hard to figure out where to actually start on a new system.
About move or die and mental checkpoint. I think they are called those awesome guys, and they have a big thing for button prompts, and making propts immediately switch to the right controller when someone begins using another one. That's why I was a bit curious.
Getting sick of the codebase, I feel that. That's a reason why a lot of games I make never get finished. Need to get better at structuring code in ways that don't end up hitting me in the back of the head. Also a big reason why I want to use typescript, it let's you write documentation right in the code, which helps immensely so you don't have to sit and figure out what the system you made 3 weeks ago does. So it might be worth a peek, it helps in just keeping you from making stupid mistakes like putting in a string where it should be a float and so on. Autocompletion and refactoring works really well in it as well.
And good luck on future projects, 1-bit art can be really cool as well, so I'll be eagerly waiting to see what you come up with heh.