Educational games are getting better. Instead of being interactive flash cards, they've become worlds where players can come to an understanding of real-life concepts. A Slower Speed of Light from the MIT Game Lab looks at what it would be like if you could walk at the speed of light. From their site:
A custom-built, open-source relativistic graphics engine allows the speed of light in the game to approach the player's own maximum walking speed. Visual effects of special relativity gradually become apparent to the player, increasing the challenge of gameplay. These effects, rendered in realtime to vertex accuracy, include the Doppler effect (red- and blue-shifting of visible light, and the shifting of infrared and ultraviolet light into the visible spectrum); the searchlight effect (increased brightness in the direction of travel); time dilation (differences in the perceived passage of time from the player and the outside world); Lorentz transformation (warping of space at near-light speeds); and the runtime effect (the ability to see objects as they were in the past, due to the travel time of light).