Nice post, I've always liked gbc mods/custom roms the best. I was wondering though, after your researching for the flasher, did you find out how big a game could possibly be?
I've always wanted to make a massive pokemon game that spanned through much more than just 2 regions like gsc did, but I've never been sure whether it was even possible or not. I've messed around with making ruby rom hacks before, but If a gbc could run a cartridge with huge amounts of data then I would probably start learning how to make gbc pokemon rom hacks.
Any light on the subject would be appreciated, thanks.