i did a similar excercise - something i found very funny, was that my half-baked emulator was getting stuck in various places in the tetris ROM. i copy-pasted the program counter hex address into the google search bar, and immediately got a reddit thread of someone doing
exactly the same thing i was, whose emulator was getting stuck in
exactly the same place in
exactly the same tetris ROM!
not only that, i think this scenario played out a few more times before i finally got tetris to play. i suppose game boy emulators are sort of the defacto 'hello world' of this type of work.