Nice 
Out of curiosity, does Processing have anything to say about whether or not the long click is “justified”, IE if processing is sending back a “Ok, fire at will” signal? Or does any long click trigger the relay?
Btw, I didn’t know about this GameControlPlus thing. Sounds interesting! I’ve been thinking a bit about sending info back to an Arduino joystick. So far I’ve briefly tried the excellent ArduinoJoystickLibrary a little while ago. But I don’t think it can send info back to the Arduino (or I don’t know how). Also, it requires an Arduino Leonardo (or I guess, any arduino with a built-in USB controller).