This document discusses using a user-centered design approach when developing exergames for elderly users. It describes conducting requirements analysis through literature reviews, observations, and focus groups. The design was iteratively tested and improved through usability testing and interviews with elderly users to gather feedback. The final exergame, called GameUp, was tailored to elderly users' needs by adjusting aspects like movement speed, visual contrasts, audio levels, and detail complexity based on their feedback. The document stresses the importance of understanding an elderly user's physical and cognitive limitations when designing technologies for them.