Advances in human-computer interaction (HCI) technologies have led to emerging computer game systems that foster physical exertion as part of the interaction; we call them exertion games. These games highlight a body-centric perspective on our interactions with computers, in contrast to traditional mouse, keyboard and gamepad interactions, not just in terms of their physical interface, but also in terms of the experiences that they support. As a result, exertion games show great promise in facilitating not only health benefits, but also novel play experiences. However, to realize this...