Gamification aims to enhance motivation for a variety of routine tasks by incorporating game elements, such as scoring points. In educational settings, students are often the players, and gamification can create a more engaging learning environment that motivates them to achieve academic success. In this paper, we describe an experimental software engineering course where we asked students enrolled in a Master’s degree program in Computer Science to play the role of game designers and develop software prototypes for the gamification of software testing education. We outline and compare their three proposals to gamify learning in software testing, which reflect team members’ diverse interests and inclinations. As a result, the proposals vary in nature, ranging from a gamified standard web application delivering exercises to a fully-fledged game. User testing provided a preliminary evaluation of their playability. Our lessons learned can guide other academics in designing similar assignments for software engineering students to develop gamification prototypes.