Early in 2013 a small Utah company walked into CES with something that looked more like abstract art than a gaming machine. The Xi3 Piston sat there as a compact metal cube, roughly four inches on each side, with indented sides and a front grille that gave it a distinctive industrial look. Valve had invested in the company and even displayed the device in its own booth. For a brief moment it seemed like this odd little box might become the foundation for a new kind of living-room gaming experience built around Steam.

Wenting Zhang looked at the M5PaperS3 and decided its e-ink screen could do more than display static pages. The compact development board from M5Stack carries an ESP32-S3 processor, a 4.7-inch 960-by-540 e-ink touchscreen, a simple buzzer, and a microSD slot. He turned the whole package into a handheld that runs original Game Boy software at a steady 60 frames per second.