http://www.doom3.com/

Two years following the unexplained disaster on Mars, the UAC returns to the abandoned facilities to investigate a mysterious beacon buried deep in the ruins of the ancient civilization.
* Battle six new demons including the hunters
* Fight in all new 8-player capture the flag arenas
* Wield new weapons including the double barreled shotgun
* Possess demonic powers to use against the enemy
* Control time to defeat the enemy and evade deadly traps
* Harness the force of gravity to control your environment
* Battle through the ancient ruins and into the horrifying depths of hell