Artist Ward Moore has on his site details about SimMars, a Maxis game that was apparently canceled in the 90s once the company realized how successful The Sims was going to be.

You can see plenty of concept art on the site. Furthermore, Mr. Moore describes the game's premise as follows:

SimMARS was intended as a role playing game, using KIM STANLEY ROBINSON Trilogy (Red Mars, Green Mars, Blue Mars) as an inspiration. The goal is to successfully colonize Mars using NASA inspired technology. The user had to creatively impliment the available martian resource and plan their living around the 6-month cycle of supply ships...Because of this premise, aesthetics revolved around the real world constraints of habitats and supplies being packaged and arriving in a chemical propelled rockets, arriving on the martian surface, after which they endure the corrosive effects of wind and radiation. Bots and Rovers are the preferred method of maintenance and travel. Coordinating assets and creatively recycling existing material creates martian civilizations.

(Thanks Superannuation and Shacknews!)