This project uses CircuitPython, a user friendly version of Python for microcontrollers. The files are just text files and are copied over to the PyGamer to the flash drive CIRCUITPY which appears when the PyGamer is attached to a computer via a USB cable.
Preparing the PyGamer with CircuitPython and Software Libraries
The PyGamer Introduction guide also has the information needed to install CircuitPython and its libraries.
See the following pages on how to perform these operations.
