The game is set on Mars and its a reboot of the original story. You will find yourself awakening while chained on an altar within UAC facility (Union Aerospace Corporation). There has been some shady experiment and the facility is now invaded by forces of hell.
You attain a praetor suit and your first weapon after you break loose from the altar and are determined to stop the invasion for good.
Apparently A game character Olivia Pierce is actually responsible for the invasion from hell.
Here are some pictures and link to a gameplay.