Health games seem to provide for attractive play experiences and promise increased effects on health-related learning, motivation and behaviour change. This chapter discusses the further possibility of mobile games acting as a springboard for communication on health and its correlations to the built environment. First, it introduces the notion of spontaneous interventions, which has been used to characterise co-design projects in which citizens seek to improve infrastructure, green and public spaces, and recreational facilities of their local neighbourhoods by adding temporary objects and installations to the built environment. Focusing on interventions, which aim to stimulate physical activity, this chapter identifies potentials and challenges to increase their impact from an ICT perspective. Second, the chapter gives an overview into current research and best practice of health games which seek to enable interaction with urban spaces through mobile and context-sensitive technologies. Specifically, it highlights "self reflective" games in which players seem to adjust their behaviour in response to interacting with real time bio-physiological and position data. Observing how mapping technology enables users to relate objective data to subjective context, the chapter identifies how health games may supplement future urban research and design in the following aspects: Raising attention to new complexes, stimulating participation, identifying locales for potential improvement and evaluating impact. The chapter concludes with an outline of future research directions to facilitate serious games supplementing health-related urban design interventions.