I have installed pico 8 with picopi on a raspberry pi zero and it runs really nicely, but I can't seem to get a zero delay usb joystick interface to work with it.
It sees a playstation classic (the mini) usb ok and also a generic nes usb controller.

If all else fails, I could just use the nes pcb and pad hack to the joystick box I'm making.
It would be far neater to use the Zero Delay - or, better still - the gpio pins, but I think you need an operating system to access those?