This developer squeezed a full Minecraft server onto an ESP32, and it actually works

A developer built Macerun, a Minecraft 1.16.5 server rewritten in C to run on an ESP32-S microcontroller. Core features work including joining, walking, block placement/breaking, procedural chunk generation, basic crafting, chat, physics, health, and hunger. Block changes are saved to flash memory. Limitations include no mobs, missing 3x3 crafting, and no persistent player inventories or positions. The project is open source on GitHub.