Exertion games, also referred to as exergames, have become popular because they combine physical activity (PA) with game mechanics, such as actions, challenges, and achievements. Exergames have been also used to encourage PA among older adults, as technological interventions to help achieve the latters’ health and wellness goals and as aids to rehabilitation. To the best of our knowledge, no systematic review of empirical studies on exergaming and older adults’ PA has been reported in the literature. Our review indicates that exergames make a measurable contribution to the improvement of health and wellness goals of older adults. Our systematic review identifies 9 categories and 19 themes of exergame applications in the domain of older adults’ PA. We aggregate these categories and themes into three broader exergaming clusters, of “training,” “rehabilitation,” and “wellness.” Additionally, we outline pathways for future empirical research into applying exergames as health and wellness interventions for older adults through physical activities.