This is a modification of pebri86's esplay micro firmware to boot directly into games (no menus)
You can find the original firmware here https://github.com/pebri86/esplay-retro-emulation
My intention was to make this device operate similarly to an original gamegear: when you turn it on, a game starts up immediately. there are no menus to select your game from. there are, however, multiple games available: you can select a different game than default by holding one of the dpad directions or the start button.
The emulator now loads the games from the internal flash memory of the ESP32 rather than from the SD card. I accomplished this in a hacky way, namely inserting the ROMs as header files, rather than using the SPIFF functionality, but it works.
youtube video I made about this project: https://youtu.be/DklmjbdR9SU
youtube video about the esplay micro device #1: https://www.youtube.com/watch?v=7j7IRWV2tp8 (not my video)
youtube video about the esplay micro device #2: https://www.youtube.com/watch?v=p0fNz_PFzWU (not my video)