Transformational games are digital computer and video applications purposefully designed to create engaging and immersive learning environments for delivering specified learning goals, outcomes and experiences. The virtual world of a transformational game becomes the social environment within which learning occurs as an outcome of the complex interaction of persons and digital resources. Engaging individuals with learning in these societal situations means concepts and skills are connected to the context and remain a powerful tool for decision making and problem solving in the world. Yet, a range of barriers need to be overcome to make a game effective for its educational purpose. In this paper we discuss the learning and game design principles explored and used to develop a nanotechnology game. The game development experience is framed by a review of the educational theory informing our project and the questions that are driving our future research as we take the nanotechnology game into the classroom to investigate its impact on students' engagement with science. We propose that transformational will be an important component of the re-crafting of teaching and learning in the digital age and that the transformational potential of computer games can extend well beyond science and even schooling. (Contains 1 figure and 1 table.)