This is a special release of Adafruit CircuitPython 4.0.0 for µGame 10.x. It is necessary, because due to last-minute changes the version of the µGame libraries included in the official 4.0.0 release doesn't work. Please use this release instead.
In order to upgrade your µGame device, please connect it to USB and press the reset button twice, then copy the circuitpython-ugame10-4.0.0.uf2 file to the TRINKETBOOT disk that appears.