Most Game Boy cartridges are just a NOR chip accessed through a parallel interface, so the only difficult part would be building the connector, then you could j

Most Game Boy cartridges are just a NOR chip accessed through a parallel interface, so the only difficult part would be building the connector, then you could just bitbang to get to the data. Unless of course you want to actually play the audio on the GameBoy, in which case the very weak CPU and unsuited SPU will make it difficult to achieve anything resembling proper audio. Of course that didn't stop people from trying, with quite impressive results given the limitations: https://www.youtube.com/watch?v=DQLTYe0Gn70 https://www.youtube.com/watch?v=DQLTYe0Gn70