Outpost 2

Description:  Outpost 2 features colony-building strategy and a mission-based, real-time, active environment that allows players to find many paths to one common goal. That goal is to build a spaceship and escape from New Terra, a planet that is ravaged by a terraforming microbe gone bad. Outpost 2 includes real-time multiplayer combat with over 2,000 types of terrain and 16-bit color including the ability to choose open-ended play or defined missions.   (From Mobygames description)