Martian Rails is a railroad building game set on a fictional planet Mars. Simultaneously, the game allows a world of canals and noble savages, a cold high altitude desert globe, a nearly airless planet, terraforming, nanotech cyberpunk and everything in between from 100+ years of science fiction stories set on Mars. The game further captures the mood of those stories and the feel of the planet. The game uses a further refinement of the wrap-around mechanism used in Lunar Rails to simulate travel across a 3D opposed to a 2D map. Having to think in 3D wraparound mode adds additional "brain-burn" to the Empire Builder franchise... sometimes the shortest distance between two points isn't the obvious straight line.
See crayon rail games for more crayon fun.