Utility class which can onlly be used in script.
game: Game object (Game)
pg_constants: Constants from PyGame (module)
down_keys: List of keys which are currently down (list)
down_mousebuttons: List of mouse buttons which are currently down (list)
get_game_object(id): Return game object which have specific id (id -> integer)
get_current_scene(): Return scene which is currently selected
stop_game(): Stop game