Superannuation discovered new SimMars images on Moore's website, while artist Corey Keller's site features art from the cancelled Castle sim. Though SimCastle was intended for a younger audience, SimMars was set to be a realistic simulation of Mars colonization based on real NASA science and technology.

Click through for Moore's description of the colony sim:

Title: SimMARS
Type: Role Playing -- Colonization of MARS in 2020-2050
Goal: Colonize Mars using real science technology (no Star Trek!)
Platform: PC

Summary:
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. (6 months being the time Earth launch to Martian arrival).

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.