Sexually transmitted infection (STI) prevalence rates are increasing in the United States and globally. Education has been found to be an important strategy for increasing STI testing and treatment rates among sexually active young adults. The goal of this project was to develop an interactive educational game suitable for young adults to decrease the social and economic burden of STIs. The health belief model informed the project. A moderated usability evaluation was conducted using the concurrent think-aloud technique. The participants (N = 5) were a purposive sample of professionals who played the interactive game and then completed Schnall, Cho, and Lie’s Health-Information Technology Usability Evaluation Scale instrument. The findings revealed the necessity of (a) an introduction screen, (b) a reward system for correct answers, and (c) avatars, while also highlighting that (d) the effect on indicator value bars is difficult to understand and (e) the timer led to a feeling of being rushed. The Cronbach’s alpha for the participant group was 0.798, the subscale “Perceived Ease of Use” achieved an alpha level of 0.815, and the subscale “Perceived Usefulness,” 0.762. Refinements to the game based on these data might help to ensure that use of the interactive game contributes to social change by increasing knowledge of STIs in the young adult population.