The use of commercial video games as rehabilitation tools, such as the Nintendo® Wii Fit™, has recently gained much interest in the physical therapy arena. However, physical rehabilitation requires accurate and appropriate tracking and feedback of performance, often not provided by existing commercial console devices or games. This paper describes the development of an application that leverages recent advances in commercial video game technology to provide fullbody control of animated virtual characters with low cost markerless tracking. The aim of this research is to develop and evaluate an interactive game-based rehabilitation tool for balance training of adults with neurological injury. This paper outlines the development and evaluation of a game-based rehabilitation tool using the PrimeSense depth sensing technology, designed to elicit specific therapeutic motions when controlling a virtual avatar in pursuit of in-game goals. A sample of nine adults participated in the initial user testing, providing feedback on the hardware and software prototype.