In this paper, we describe a pervasive treasure hunting game: ''Team exploration'' based on the Transhumance mobile ad-hoc network platform. The testers of this game came up with innovative suggestions that combined the technical features of the platform with their urban experience. They pointed to specific aspects of urban mobility that influence pervasive game design and contribute to the user's pleasure. These tests show that the notion of space (geometrical organization) is not enough to characterize and organize pervasive games and that four main anthropological features have to be taken into consideration: the concrete city (physical organization), the imaginary city (narratives), the functional city (services) and the city events. The multilayered urban experience is also defined by our schedules (including repetitive or exceptional events) and by our assessment of other users (the distance or proximity as they are felt). These diverse aspects and qualifications of urban experience provide an interesting framework for the understanding of pervasive game experimentations, as well as point to new directions in pervasive game design. Our paper advocates that further anthropological observations are part of the pervasive game design methodology.