Software and applications of augmented reality (AR), virtual reality (VR), and mixed reality (MR) technology combined with game/gamification techniques in healthcare have increasingly been studied in academia. However, there is a need to explore the usage, challenges and opportunities of AR/VR/MR game/gamification software/applications in the healthcare system. To explore this, we present an online survey conducted in the healthcare-relevant system (including hospital-based system, homecare-based system, institute and university, and industry). Based on the answers, we found examples of digital games and AR/VR/MR applications used in healthcare, as well as some general information (name and feature, purpose, target user, and use occasion), usage situation, and user experience. This presented survey is beneficial for both researchers and developers in computer science and medical science. It can familiarise them with existing products and their current use, advantages and potential issues of AR/VR/MR and game applications in healthcare. In future work, the survey would be extended to obtain other user experiences and feedback of AR/VR/MR techniques and game/gamification technology applied to healthcare, as well as to study how to overcome the challenges, and develop the opportunities further.