In physiotherapy, the traditional approach of using fixed aids to train patients to keep their balance is often ineffective, due to the tendency of people to lose interest in the training or to lose confidence in their ability to finish the training. A Trainer system is proposed on traditional physiotherapy treatment methods to allow patients to play qualified and immersive games with a mobile aid. Using RF localization and self-balancing technology, the system allows patients to control a vehicle with their sense of balance. This platform provides a series of game feedback interface which involves part-body motion in sitting manipulation therapy to make the rehabilitation more flexible and more effective. This paper reports the designing and the control of the Trainer, the experimental evaluations of the performance of system, as well as an exploration of the future work in detail. Our work is intended to improve the patient experience of the physiotherapy rehabilitation using games with instinctive ways of controlling mobile instruments.