Alien Invasion: S.U.M.1

The film follows Private S.U.M.1, a soldier living in a post-apocalyptic Earth. He is serving on a hundred-day mission outside Exilium, the highly fortified compound housing the human survivors of an alien invasion. S.U.M.1 is assigned to an outpost to monitor and secure a remote bunker which is part of a defense circle surrounding the compound. Read more on Wikipedia.