INTRODUCTION: Serious games is an effort to combine the engagement and motivation from games with some sort of utility beyond mere entertainment. OBJECTIVES: The objective of this paper is to revisit and analyse six projects to explore the design space for serious games and derive design guidelines for serious games. METHODS: We analysed our project portfolio to identify a set of projects which satisfied well-established guidelines for design science research. By analysing these projects as well as their outcomes we generated a set of design principles for serious games. RESULTS: The results from this study is a conceptualisation of the design space for serious games and seven design principles. CONCLUSION: By explicating the game design co...