In this paper we present the design and exploratory evaluation of Molarcropolis, a mobile persuasive game to raise adolescents' oral health and dental hygiene awareness. The game uses strategies of persuasion to reach the aforementioned target behavior. During the game, players receive information on oral illnesses and their causes, habits and activities that put adolescents in a special risk situation, and tips on improving oral health. In an exploratory evaluation, adolescents indicated that the game is both entertaining and informative, they learn new aspects of their oral health, and it has potential to change oral health habits. © ACM 2009.