'The Magic Stone' is a video game whose main aim is to help people with Down syndrome to improve communication skills that have been affected due to their disability, especially those related with prosody. The interface of the video game includes a number of elements to motivate the users to practice and train their pronunciation. The usability tests of the system have reported high degrees of satisfaction of users and trainers. Perception tests have permitted to confirm that players improve the use of prosody with the use