The growing demand for sustainable products and services has led to the emergence of a range of entrepreneurial opportunities for innovative business solutions. These new opportunities require novel entrepreneurial skills to design, grow, and maintain sustainable businesses. However, existing educational games do not address the specific skills needed for sustainable entrepreneurship. This work introduces an interactive business game that enables learning in an engaging and practical way to prepare learners to become the entrepreneurs of tomorrow. Our business game is intended to increase learners’ self-assessed skills and self-confidence by at least one point on the five-point Likert scale. The game is embedded into a didactic framework accompanied by a lecture and discussion part where learners manage their bike rental business and self-reflect on their decisions. The game scenario allows the players to guide their business through three growth stages: survival, growth, and expansion. In this study, 151 high school students participated in the evaluation across all stages. They assessed their knowledge in a pretest and a posttest and judged the developed game on its ease of use. The learners’ sustainable entrepreneurship knowledge and skills improved significantly. This study thus confirms the mixed approach as a viable teaching tool for this area of expertise. Furthermore, a holistic didactic framework with an introduction to the game and subsequent debriefing contributes to the success of the business game too. A sign test and bootstrapping with confidence intervals constituted a simple means of statistically quantifying the learners’ improvement.