BattleDroids is a programming and development game where you program a robot (the "BattleDroid" or just "droid") that you build or purchase, then program to play, explore, or compete against other droids and their pilots. Your droid has the ability to move, sense its environment, and engage opponents, but you -- as the pilot -- have to tell it what and how to do it via programming the droid's processing unit.
Originally designed and developed for the Atmel (now Microchip) AVR line of 8-bit microcontrollers. It was extended to the 16-bit XMEGA platform, but ARM (via ATMEL SAM and STM32) was becoming more popular and accessible to the hobbyist. Now, RISC-V is all the rage and is open hardware, so this architecture is being considered for support.
In BattleDroids, it's some unspecified near-far future, mankind has been at war for decades, and you are in control of a piece of retro technology salvaged from the scraps still left to be found in the world. With this droid, you are able to explore your environment, collect data via various sensors, or test your pilot skills against the ultimate opponent: another droid and its pilot.