You can't go wrong with the default Raspberry Pi OS but there's also no reason you couldn't set it up as a gaming rig using RetroPie. If you want to get a closer look at this Raspberry Pi project ...
"It comes with everything you need to complete it, except a Raspberry Pi, which you have to purchase separately." The PiCar-X is compatible with the Pi 5, 4, 3B, 3B+, and Zero 2 W. The basic kit ...