I'll check DDRKirby out, thanks for the rec!
Also haha I actually wrote custom physics/collision for this game and TRYH4RD, because I was in gamejam mode when I first wrote my systems code and forgot to check if Love2D had physics already. I should probably switch to the Love2D physics/collision stuff eventually (I think it's just a wrapper around Box2D) since it'd be faster and better tested.
I feel like getting sick of a codebase for me is inevitable towards the end of a project. The cleaner my initial code is, the longer I can stave off that feeling, but so far with my projects they almost always end with pure spaghetti code. That could just be burnout too though, so it definitely varies.
I made a game that I ended up never releasing last year with a custom JavaScript engine (which I ended up porting to TypeScript later on as an exercise); It's definitely super easy to use, and the lack of type checking in lua definitely bites me a decent amount. If you end up using lua for your next game and Love2D, I highly recommend the EmmyLua VS Code extension (if you use VSCode), it gives you autocomplete for all your custom lua code which was a lifesaver in this project.
Good luck with your future stuff as well! Always looking forward to what you put out!