Preventing falls is extremely important today as people live long sedentary lives. Fall prevention platforms can help, by stimulating seniors to perform exercises that improve balance and muscular strength. However, existing platforms for fall prevention mostly target individual users exercising at home. This paper describes the design and evaluation of a multi-player fall prevention game platform, FallSensing Games, to be used in senior care centers. The game design was inspired by the Otago Exercise Programme and the evaluation focused on biomechanical parameters, game experience, and technology acceptance. Results showed that the game was easy to follow, that seniors performed exercises correctly, and that the game integrated well with the activities of the senior care centers. Lessons learned from this project may inspire the development of similar platforms, and, in this way, support group exercise practices at senior care centers.