Gamification has captured the interest of both Human-Computer Interaction and Educational Sciences during the last past years. However, most of the available case studies in the literature are not focused in online higher education environments, even less considering the demographics of adult learners. This paper presents the design and development of an online gameful course of Computer Networks formed by two groups with an average age older than the common university students. This approach aims to encourage adult learners to solve non-graded formative activities and to increase their sense of kinship to the group. After one semester, the results revealed a moderate effect on student engagement, but a low enrolment rate. In contrast, a similar previous study revealed promising outcomes. The main goal of this work is to present the obtained results and to analyse the relevant issues in order to understand the source of the engagement differences perceived.
