A "state function" that builds both lists and calls play_menu() to do the display
Thus, we get a simple implementation of all desired menu-states
in a simple function and two object lists, The lists are cleared between menu-states.
method is taking care of running the actual game and game-demo.
The difference between the cases is the input source for player
When running a game player input
is defined as keyboard and for demo mode it would be an appropriate demo-stream.