Great game! Once you play it it covers your mind for several days!
The storyline's about humans who are trying to colonize Mars and who met the "grey" aliens, which there actually Taars, who are trying to do the same thing. The Taars have left there planet many years ago for the same reason as the humans are trying to colonize mars- no more natural resources and the planet 's destroyed! 1st the Taars wanted to colonize Earth but they saw that the planet is on the edge of destruction!
As the game describes the two civilizations start a bloody war over Mars. The game's pretty banal in terms of storyline until the discovery of Mars' Ancient Artifacts. Then a human commander is abducted by the aliens and they play with his mind making his company an enemy of the Humans. Then in the Grey campaign you take contact with Taars on Earth left behind after the Roosevelt accident.
The game makes a good job, scaring you with the hundred alien demon-like and bug-eyed creatures atacking you continuously in the first missions. You go to sleep thinking to whats the best tactic to defend your base without losing to much troops (which have various forms and functions). The great cutscenes are a rewarding reward after completing or losing a level.
The end is mysterious. In the human ending an wrong triggered artifact wakes deep buried in water monsters, and in the grey ending a great fleet atackes Earth.
Dark Colony's a great game worth be trying by any sci-fi, aliens, or strategy games fans!