This article presents the validation of the Pervasive GameFlow model (PGF), a model for analyzing player enjoyment in pervasive gaming. The model can be used as both a heuristic guideline for designers and as evaluation criteria in user-centered evaluation of pervasive games, but also as a framework for understanding player experiences in pervasive gaming on a more general level. The theoretical background and perspective on game design and the design- support approach that the PGF model represents are explained, and the concept of the magic circle is discussed. The eight elements of the PGF model (concentration, challenge, player skills, control, clear goals, feedback, immersion, and social interaction) were validated by evaluating a crossmedia game prototype (a subgenre of pervasive games) called Furiae. The comparative importance of the eight elements of the PGF model and their effects on the pervasive gaming experience was a focus of the evaluation, in which questionnaires (qualitative) and focus group interviews were used to capture how the players graded the importance of the eight elements in playing Furiae. The study revealed that seven of the eight elements seem to be of specific importance, as they scored relatively high in the validation. The top three elements according to the results are concentration (games should require concentration and the player should be able to concentrate on the game); challenge (games should be sufficiently challenging and match the player's skill level); and immersion (players should experience deep but effortless involvement in the game). Finally, implications for design are discussed in terms of how some of the most important elements present challenges and possibilities for crossmedia game development.