This publication describes the analysis and development of a serious game for the rehabilitation of stroke patients, which was conducted with the assistance of an experienced physiotherapist using a user-centered design. After a stroke, patients often complain about balance related problems or partial paralysis. Normal rehabilitation training depends on balance and strength exercises. In such cases balance plates are often used as training devices, but patients often report lack of motivation especially when training at home. The research objective of this publication was to develop a serious game using the Nintendo Wii Fit Balance Board. From a physiotherapeutic view it should help patients suffering from a stroke throughout their rehabilitation, especially to increase the motivation to do their exercises. Since every patient is different, the developed serious game can be customized by a physiotherapist for the individual patient’s needs. A lot of customization options provide optimal support for the entire rehabilitation process.