This paper describes a video game for the rehabilitation of the pronation and supination movements of children with cerebral palsy. It is used as an interface for a robot that is currently under development. The game was programmed in LabVIEW and MATLAB is used for analyzing the results. It simulates a formula one racecar on a racetrack. Its objective is to keep the car inside the racetrack's limits. The pronation and supination movements control the car's horizontal position on the screen. A first preliminary test was done with a healthy 11-year-old right-handed child. The same racetrack was played 5 times with each arm. The results showed that the child had an average difference of 3.32% against the expected path when she used her right arm and an average difference of 3.86% against the expected path when the left arm was used. Future improvements will be taken into account, for example, the use of the robot's motor in order to give assistance or resistance to the arm movements of the patient.