Could the button be in the UI only? And could you like make the keyboard map to the button as well as onscreen?
I am going to map Mouse click / one keyboard key / one controller key all to one action. This is just for accessibility so one can play with only mouse/keyboard/touchscreen/controller available. The rules state “Create a game that utilizes just one button.”. In my interpretation it is fine if a game maps multiple inputs to one “button” action as still only the use of one of these is needed to play the game. But of cause West Valley Games make the rules. So please tell me if my interpretation is wrong. However “That is the only button the player can use” would support my interpretation.