The level of detail alone is remarkable. True to the program's focus on realism, maps of Mars are all based on NASA data, and all the data in the game is accurate, down to the smallest detail in the Martian calendar. Your Mars settlement consists of many modules including living quarters, sickbay, lab, rover garage, and greenhouse. You explore Mars by sending out rovers from the base, each of which must be manned by a crew and regularly maintained.

Similar to SimIsle, assigning individual settlers to different tasks is the heart of the simulation. You can tell them to collect rock samples, drive a rover, help out with farming in the greenhouse, and many other tasks. Each person has an inventory, health indicator (fatiqued settlers perform tasks poorly), and different skill levels in different areas (driving, mechanic, EVA operations, etc.) that determine how good he/she is at doing the task at hand. Similar to RPGs, the settlers even have "natural attributes" (similar to RPG character statistics) that determine how effective they can be at certain tasks. These attributes range from typical ones such as strength, endurance, and agility, to less common ones such as (physical) attractiveness, leadership, and presence (the ability to stand out in a crowd). In addition, the settlers' skills can be increased with experience in relevant tasks.

If you enjoy realistic space/colony simulations, Mars Simulation Project is well worth your time. Although it is not a "game" as such due to lack of overall goals or objectives (although the author notes that it may be turned into a game at some point in the future), it is still a lot of fun to explore the virtual Mars and see what it takes to maintain a smooth-running settlement. Best of all, the download comes complete with the source code, which helps make a project a dynamic one, with consistent updates from enthusiasts who program their own additions into the program. Two thumbs up, way up!