Disease of the lower limb musculoskeletal system is one of the most common diseases in elders. The use of interactive somatosensory games (ISGs) in rehabilitation has been widely used. Most relevant studies have focused on efficacy, while only a few have investigated the difficulties, willingness, and requirements of elderly people in playing the game. Therefore, this study is to design an ISG that is focused on lower-limb rehabilitation and to explore whether the designed ISG can enhance the willingness and motivation of elders to undergo rehabilitation. In this study, 15 elders (5 males and 10 females with average age of 78 years) with degenerative joint disease were recruited to participate in our pretest-posttest design experiments. First, the subjects completed a five-minute pre-test questionnaire after a one-minute traditional rehabilitation (TR). Second, they completed a five-minute post-test questionnaire after a one-minute interactive somatosensory game rehabilitation (ISGR). The average experiment time for each subject was 25 min. We used a t-test to analyze the data. According to the result, there are significant differences in four factors (i.e., interest (t=-6.89, p<0.05), self-affirmation (t=-3.17, p<0.05), understanding of rehabilitation states (t=-3.31, p<0.05), and fatigue (t=2.49, p<0.05)). The results show that (1) for the same treatment arrangement, ISGR can make the elderly people more interested in and reduce their fatigue while undertaking the long-term rehabilitation; (2) using ISGR can increase their understanding of, and their confidence in, their rehabilitation states; and (3) elders generally have positive attitudes toward the ISGR. The results and analysis of willingness and needs in this study can be as a reference for future studies of rehabilitation game development, and the development of rehabilitation to improve the health of the elders.