A continually existing skills gap in the technology industry’s workforce prevents many organizations from creating truly accessible products and services according to the Web Content Accessibility Guidelines (WCAG) standards, increasing their risk of alienating and excluding a significant portion of users. Software professionals’ low accessibility skills are largely attributed to the lack of coverage of accessibility topics in the Computer Science (CS) curriculum. While prior literature explores some active-learning pedagogies like project-based learning and delves into incorporating accessibility topics in the CS curricula, game-based learning to teach accessibility has not been explored enough. This study aims to develop and assess the effectiveness of a serious game to teach accessibility to computing students and software professionals.