A new chapter in the "Halo" saga opens up today with the launch of "Halo 3: ODST".

The game takes players back in time to experience the "Halo" universe from a whole new perspective as an Orbital Drop Shock Trooper.

The new game also gets "Firefight", a new cooperative multiplayer mode where up to four players "battle waves of unrelenting Covenant onslaughts".

Halo 3: ODST is available now for the Xbox 360 from around £30.