We introduce a location--based game called Feeding Yoshi that provides an example of seamful design, in which key characteristics of its underlying technologies-the coverage and security characteristics of WiFi-are exposed as a core element of gameplay. Feeding Yoshi is also a long--term, wide--area game, being played over a week between three different cities during an initial user study. The study, drawing on participant diaries and interviews, supported by observation and analysis of system logs, reveals players' reactions to the game. We see the different ways in which they embedded play into the patterns of their daily lives, augmenting existing practices and creating new ones, and observe the impact of varying location on both the ease and feel of play. We identify potential design extensions to Feeding Yoshi and conclude that seamful design provides a route to creating engaging experiences that are well adapted to their underlying technologies.