Well done learning all that from scratch! It feels great to make something 100% original. I'll have to check out Bosca Caoil; I use LMMS for my music (also free/open source).
I like how you leverage the rules of tetris in your game for accessibility (the way you put a spin on it was also really clever). It's kinda like using chess as a base game; pretty universally understood set of rules that you can build off of.