I noticed in the list of commands does not include 'start' and 'select' (i looked at the kerTable. file referred to on adafruit tutorial) so maybe it should be SPACE and ENTER, I tried this but still does not work in emulationstation or when playing a game.
I am just using arcade buttons and a joystick.
Just to check, does the part after the # matter? I thought this was just a reference in the code to the person reading it so they knew what that button/PIN did.