Sci-Fi

Sci-Fi themed games are games that are characteristic of science fiction literature; the narrative is dependent on the impact of scientific discoveries that do not yet exist in reality. Some games, such as those in the Half-Life series and Unreal series take place in a sci-fi universe that was created specifically for the purpose of the games. Others may take place in existing sci-fi universes, such as licensed Star Wars games. Common elements of sci-fi themed games include futuristic settings, high-tech items and weapons, and alien characters.

Homeworld

The first fully three-dimensional real-time strategy game. Released in 1999.
Other parts of the series are Homeworld: Cataclysm (2000) and Homeworld 2 (2003).