A game is the simplest playable representation of complexity
Complexity is not the same as 'complicated'. The best entertainment and serious games are essentially very simple. Adding more elements to a game does not necessarily make it more engaging. With more information, actions and rules, a serious game is not necessarily better for learning or decision-making. As in art and writing, 'less' can be 'more'. Dennis Meadows called it 'learning to be simple'. Some of his games, like Harvest or the Hoop, demonstrate persuasively that complex behavior can be experienced with just a few players, trivial objects and rules. Of course, there can be many reasons why a serious game needs a larger number of game-elements and rules. Players often want to see in the game the many variables from their professional life. However, when complex behavior turns into complicated behavior, the point of the matter gets lost.