Mobile is the fastest growing area for computer gaming. Fueled by the every growing sales of handheld devices, the increasing comfort of gamers with their devices, larger screens and availability of casual games, mobile games offer the developer an area of rapid growth. In this paper we report on the commencement of research that attempts to identify the key development concepts for a mobile game. Gamers’ locus of controlis examined to determine the extent to which this personality trait impacts both interest level and type of game. We consider two mobile games, Grand Theft Auto and Edge, in an attempt to isolate the important design characteristics for this medium.