Firefight mode is excellent, challenging and great multiplayer, though the campaign is very short. 9/10
The campaign is set in the city of New Mombosa. You complete missions in any order you please. Although the campaign mode is short the game is excellent and is well worth the money with great multiplayer modes online and offline. The campaign mode only lasts just over four hours which isn't as good as previous installments.
Bungie along with Microsoft has done a great jon reinventing the Halo serious and a change of direction for the serious.
If you enjoyed any of the previous Halo games then Halo 3 ODST is for you!!!!