WASD- scroll left/right- "turn"/accelerate your frame of reference press mouse- paint In the background, the two yellow lines indicate paths that could be taken by things going the speed of light. The white lines indicate the origin point's time and space axes.
This is a paint program, except instead of painting on a 2D world, you paint on a 1+1D world - one dimension of space and one of time. This is a sheet of a 1-dimensional world's history where 'up' is into the future and 'down' is into the past, and "turning" is more like changing your velocity so that you will be in a different location in the future. Your range of velocities is limited for technical reasons. In-universe, you can accelerate as fast as you want for as long as you want, but your path will never match up with the lines taken by light.
