Halo 3 - Master the Multiplayer

ISOLATION (download guide)

Bungie says: "Containment protocols are almost impervious to pre-Gravemind infestations. What could possibly go wrong? 2-10 players."

GamesRadar translates: Snipers, welcome to your new home. The entire map can be viewed at once, excluding the tunnels... and no one wants to hang out down there.