Another consequence of relativity is concentrating the light from objects in front of you - and to the sides. It's called relativistic aberration. Objects on either side start to enter the field of view in the front, and the world starts to look like it does through a fish-eye lens. It also means anything in front of you looks brighter. Move backwards, and the world seems to go darker as the light waves you can see come from a narrower and narrower field.
The game also adds in time dilation and altering the length of space dimensions in the direction of motion. As one approaches the speed of light, time slows down –- the observer's clock moves more slowly than a stationary one. This is the source of the "twin paradox" in which one twin who travels near the speed of light for years ages more slowly than her sister on Earth, though the slowly aging twin doesn't notice until she returns to her now-older sisiter. (It's also a common plot device in science fiction novels, notably Joe Haldeman's The Forever War).
Testing Relativity With Two Dead Stars
Less well-known is the shortening of length dimensions -– a moving object looks shorter in its direction of motion, so a person running by at near light speed would look as though they had been flattened to an outside observer. The runner wouldn't see any difference.
The result is a world where everything bends and other objects seem to slow down, and it becomes difficult not to overshoot targets.
The game might be too simple for some people but it doesn't have to stay that way: the code is open source, so anyone who wants to design a game in the world governed by relativity will be able to do so.
Photo: The world at about 25 percent lightspeed. Credit: MIT Game Lab