The widespread use of sophisticated mobile computing devices has set the stage for a renaissance in audio only entertainment. Traditional visual games are already used widely in cellular phones and similar devices. A significant limitation is the small display size. In contrast, audio only games on suitable mobile hardware need not degrade due to the smaller form factor. This makes audio only games an attractive alternative to visual games. We describe a framework for authoring interactive narrative-based audio only games set in 3D virtual environments. Despite the novelty in audio only gaming, our approach builds on a foundation of several years of research into audio only applications for sight impaired users, augmented reality systems and human-computer interaction studies. In comparison to attempts to provide a realistic user interface, we argue a simple interface enhances both immersion and entertainment value, serendipitously making audio only games practical for mobile computing. Novel features of our system include real-time gameplay and multi-player support. We also describe our software architecture, the current implementation of which uses low-cost existing PC-based hardware and software. In addition, we describe our first game, Dragon's Roar.