Children with cerebral palsy (CP) often have limited upper extremity (UE) control, Virtual reality (VR) is a current technology being evaluated as a form of UE therapy for children with CP, The systems currently available have been developed with games that cannot be graded to match the skill level of children with severely impaired UE control. A novel video game platform, "Hands-Up", has been developed at New Jersey Institute of Technology. The platform features software that allows for the customization of games and encourages users to make purposeful UE movements. To quantify changes and improvement in movement due to increased game play, a MATLAB-based toolbox of functions was developed. The functions include measures of peak velocity, percentage time to peak velocity, number of movement units, and straightness ratio. Data collected during reaching tasks were analyzed to validate the toolbox. The toolbox of functions provides different ways to interpret user intent.