Thank you very much for playing and the kind words!
I built and made everything from scratch! I'm mainly an artist so even though it's definitely inspired by Pokémon and Zelda on Game Boy, it's all original art. I've also been programming for 10 years now and I always prefer writing stuff myself as a challenge and to keep everything clean and in control. So I can't really help you with that, I also can't recommend any frameworks that might exist as I've never tried or looked for any...
I wish you all the best with your project though :)