If you've played the Civilization games before, you'll be fully aware of those pesky barbarian hordes. However, in the new Civilization: Beyond Earth, you'd be wrong for thinking the aliens will act just like the barbarians, as we're shown in the below video from Firaxis Games.
Pete Murray from Firaxis talks us through how the aliens act like another faction, and have their own complex tactics. Initially he begins the game and treats the aliens as if they were like the barbarians, playing aggressively and eliminating any aliens he comes across.
In the final portion of the video Murray restarts the game and takes a different approach towards the aliens. Watch out for the background entertainment at the 32:42 mark.