@racoon
Diverting from this thread to keep QMK in this one.
Another modification (download)
joystick Y = Left mouse
joystick X = Right mouse
joystick B = Shift
joystick A = Win
Fn+g should toggle back to game mode buttons but I don’t have any gaming stuff to test with.
In light of all the problems OE4DNS had above, maybe start with olly’s 20240922 version (just in case 
) and then update to this as per olly’s instructions.