With the increasing of ageing all over the world, elderly health attracts more and more attention. This paper aims to study existing extended reality (XR) game applications for physical exercise through a literature review with 14 papers as an outcome. Based on these papers, we explored the contributions, opportunities, and challenges of exercise XR games for the elderly. The papers were analysed based on several perspectives, including publication information, design and implementation, game information, teamwork and social games, evaluation, and advantages and disadvantages. We found that the elderly were interested in and accepted the use of XR games. The positive effect of such games was common in the research results. Even if there were problems, such as simulator sickness, safety risks. device problems, and cost, there are still opportunities and space for research and development in the future. The overall positive attitudes toward XR exercise games for the elderly could be seen by both researchers, developers, and users. However, these game applications also presented some problems and future improvements are needed. The presented review is beneficial for researchers and developers to create or enhance future XR applications by learning from existing work.