The importance and benefit of group work is nowadays widely recognized and acknowledged in education. Group work can be supported by online shared workspaces that allow group collaboration. However, the e-assessment of group work remains an issue. Most of the existing strategies rely on intra-group peer assessment to evaluate individual contribution to group work. We propose an alternative by introducing some gamification components. The assessment of students' individual involvement and performance is then shifted to the engagement of students to contribute and participate into a learning community. The goal is to create an enabling environment to stimulate learning by peer sharing and formative feedback. This paper describes the approach, the online learning platform and some of the latest results.