The turn of phrase “work hard, play hard” distinguishes work and play as two distinct areas of life. They are separated by a rigid comma that prevents any unwanted spillover. In four words, the statement illustrates the role of play in the everyday life of a 21st century adult.
Both are studiously kept apart and yet, both matter.
A closer look at play and games in the context of work reveals that the distinction between these two spheres of life has been blurred for rather a long time.