Dawson Pate has created BitByte, a Teensy 4.1-based handheld console with an easy-to-learn scripting language for creating your own games.
The Micro VM language allows games to be edited as simple text files on a microSD card, which is automatically mounted as a mass storage device when connected via USB.
The handheld features a 2.8″ 320×240 LCD display, an ESP32-S3 coprocessor for wireless multiplayer, dual piezos for sound, and 18 GPIO pins for incorporating additional hardware.
The MicroVM language includes tilemap, ray-casting, texturing, and more, in order to facilitate game development.
Games developed in the language are inherently open for analysis and modification since there is no compiled binary. The Arduino IDE can be used to create your own firmware without the VM. The project is currently crowdfunding on Kickstarter.