As in Gears of War (i.e., the Kryll), the player will discover that being surrounded by darkness is a bad thing. One example is the sunken Library of the monastery. The stairs on either side of the room lead only to darkness and death; only by jumping across the tops of the bookcases (and, thus, remaining in the hazy glow of the alien lights) will the player be able to traverse the room.
The first image that the player will see is the--hopefully--awe-inspiring view of the monastery facade surrounded by the alien dome. The pale, artificial light has caused the foliage to wither and many of the structures are crumbling from neglect. Creepy alien devices cover parts of the building in an aesthetic that is Star Trek's Borg crossed with the mechanisms in Event Horizon (e.g., "heavy metallic, spikey, alien look").
Both of these images basically started as pencil drawings which I scanned and colored using Photoshop. I'm still getting my feet wet regarding the use of color, but I'm fairly pleased with how these images turned out.