This paper describes an ongoing project to build a computer application that presents Einstein?s Theory of Relativity in an interactive game environment. With the current interest in the use and study of how computer games can help teach and educate, so-called ?serious games?, the resulting game is expected to have value for educators in communicating the concepts of Relativity to high school students as well as introducing the topic to a wider audience. The focus of this paper is on the initial design and building of an Asteroids-styled game and describes features of the physics, graphics and animations, and play mechanics. Directions for future development and studies are discussed.