After you have beaten your first arrival on Halo your troop has been recovered and you could fly to the other side of the ring. Your mission is to stop Tartarus from using the index....
Play a whole big map from the Halo campaign
Defeat lots of Covenant like, Grunts, Elites, Heavy Elites, Jackals,Jackal Snipers, Hunters, Flood, Wraiths, Ghosts, Covenant Dropships....
Get one of 14 different weapons from UNSC and Covenants each must be fired manual.
Get different grenades like frag grenades , plasma grenades and emp grenades.
In some parts of the map you can take control of vehicles like warthog, ghost or scorpion.