I found out (too late in the night to act on it) that there is a community driven Guitar Hero clone called Clone Hero and there are sole tools to make the Riffmaster work with it. I'll be looking into that today.

Holy shit that's exactly what I was thinking. Thanks for sharing this. I'll dive into it a bit more.

How has your experience been with the Playdate? Does it have any Game Boy Emulation or is it native games only?

In my case they need to be locally connected to the phone so my companion app can populates them.