When rehabilitation sessions are for maintaining capacities, the demotivation of patients is common due to the difficulty in improving their situation. Recent experiments show that rehabilitation results are better when users are motivated and serious games can help to motivate patients in rehabilitation processes. We developed a rehabilitation serious-game for a set of patients who had abandoned therapy due to demotivation in the previous years. The serious-game was developed following desirable features for rehabilitation serious-games presented in the related research works. From this development, we present implementations guidelines for developing serious-games as motivational tool for rehabilitation therapies. The experiments performed in previous works validate that the interacting design issues defined help motivation in therapy and that they are adequate in rehabilitation therapy.