It's done!

Now you can play old retro Nintendo Game Boy games on ESPboy

Mario, Zelda, Kirby, etc...

Nintendo Game Boy is an 8-bit handheld game console developed and manufactured by Nintendo. It was first released in Japan on April 21, 1989. The Game Boy combines features from both the NES home system and Game & Watch hardware. The Game Boy and its successor, the Game Boy Color, have sold an estimated 118 million units worldwide. It is one of the most recognizable devices from the 1990s, becoming a cultural icon in the years following its release.

Here is the source code

Thanks to @deltabeard for Peanut-GB emulation core!