Background Physiological changes resulting from aging can impair postural balance. Exergames have been used to treat balance disorders, enabling sensory-motor training due to their content, and with targeted goals and purposes beyond entertainment. Aim The aim of this investigation was to describe the development of a serious game, VirtualTer, and to test content validity. Methods A Brazilian group from the Federal University of Rio Grande do Norte developed a serious game called VirtualTer for postural balance rehabilitation in older adults. In game navigation, the avatar needed to save the environment from catching harmful energy that destroys nature. The avatar performs stationary walking, lateral reaching, and climbing up and down steps to capture the energies. Content validity was determined using content matter experts by the Delphi method. Eleven content matter experts played the game and expressed their opinions using the assessment instruments: VirtualTer Dimensions (VD) and System Usability Scale (SUS). Results VirtualTer was designed with regard to variability in practice, since the game was constructed under three levels and offers continuous and terminal feedback. The participants needed to achieve at least 70% of the total score to advance to the next phase. The limits of stability for lateral reach test were right 23.2 +/- 4.77 cm and left 22.9 +/- 4.86 cm, which was applied in the game. The content validity index of the VD was 0.8, and Cronbach's alpha coefficient was 0.924. The content matter experts reported the game as having a 67.73 satisfaction with the SUS. Conclusion This game has good usability, low-cost investment, and supports access to innovative and valid technology for rehabilitation in countries with little investment in technology for health.
