Statistics show that urban green public spaces deteriorate globally. In African cities, where the urbanization rates are the highest in the world, public spaces quickly disappear under layers of garbage or are grabbed. For public authorities having to deal with other pressing socio-economic challenges in the context of outdated regulations, insufficient capacity and resources and wide-spread corruption, public spaces are not a priority. However, the research worldwide has demonstrated the potential of public spaces to become the key catalyst of socio-economic growth given their environmental, economic and social benefits that are however largely ignored by public authorities and the general public in African cities. This article suggests a citizen-driven public space upgrading movement can address these challenges and presents a gamification approach for citizen mobilization and raising awareness: The Changing Faces Competition that has been piloted by Nairobi-based organizations Dandora Transformation League and Public Space Network.