We show here how integrating novel natural user interfaces, like Microsoft Kinect, with a fully adappatient's current statustive game engine, a system that can be used for rehabilitation at home can be built. A wide variety of game scenarios, a balanced scoring system, quantitative and qualitative exercise evaluation, automatic gameplay level adaptation to patient's current status, and audiovisual feed-back are all implemented inside the Intelligent Game Engine for Rehabilitation here introduced, and are aimed at maximizing patient's motivation and rehabilitation effectiveness. The system is integrated into a multi-level platform that provides continuous monitoring by the hospital and it has been developed inside the framework of the EU funded Rewire project.