In this paper, we discuss the potential role of immersive interactive games in public engagement with environmental science, in this case flood risk management. Recent high magnitude storm events in the UK have fuelled great public interest in flooding. However, there remains an apparent mismatch between the scientific voice of flooding research and the wider public discourse, which we argue games may be able to address. Downpour! is a street game that casts players as flood risk advisers in a fictional flooding scenario. Players work in teams to respond to an immediate crisis and make longer-term decisions about mitigation through a series of encounters with actors, films, puzzles and treasure hunts. The game was created by a street game designer in collaboration with film-makers, environmental scientists and public institutions, with performances at the Manchester Science Festival and the Festival of Social Science 2016. Based on observations and responses from these events, we discuss how the game fostered understanding of, and engagement with, decision-making in flood risk management. Games offer people the agency to experiment with decisions in a safe space. As a result, we found that players begin to independently interrogate both scientific and political dimensions of flood management. The immersive nature of a street game further creates an emotional connection with the issues, which has the potential for triggering active involvement in flood-related efforts. We conclude by reflecting on the process behind the game creation, commenting on the strengths and difficulties of innovative collaborations between environmental scientists and creative practitioners.