Ok, sorry, @Agent_14. The game.elf files support, directly and without McAirpos, at least EV_KEY(digital) input handles with key values from 0 to 1000 in its /sd/arcade.cfg file for SCAN_CODES=/dev/input/eventX.(source)
This can be for 2 players on either 1 keyboard or 1 controller, as far as I have managed to figure out.
But many controllers have gradual/analog directional controls(EV_ABS), which I haven’t figured out how to work in this file, though some findings from the bonnet suggest it might also be supported somehow.
With McAirpos EV_ABS and EV_KEY inputs are translated/mapped to EV_KEY in /sd/arcade.cfg, and up to 2 controllers of many different types should work out of the box(see list of supported controllers known so far).
If not mapped correctly out of the box, you can edit the ~/McAirpos/McAirpos/uinput-mapper/configs/arcade1&2.py according to your the input event handler codes defined for your controller(s).
These codes can be found by testing your controller with e.g. the app evtest or .../uinput-mapper/input-read -C - D /dev/input/eventX, where X is the input event number for your controller