 In a July 2008 interview with MTV , Microsoft 's head of Xbox business , Don Mattrick , stated that Bungie was working on a new Halo game for Microsoft , independent of other Halo projects . An announcement of the new Halo project was expected at the 2008 E3 game exposition , which Bungie stated " has been building for several months " , but was delayed by their publisher Microsoft . The Halo announcement was to be part of Microsoft 's 150 @-@ minute E3 presentation , and was cut to trim the presentation down to 90 minutes ; Microsoft stated it wanted to give the game its own dedicated event . After the release of an ambiguous teaser trailer on September 25 , the project was revealed as Halo 3 : Recon , later changed to Halo 3 : ODST . Set between the events of Halo 2 and Halo 3 , players take control of elite human soldiers called Orbital Drop Shock Troopers ( ODST ) . The game was released on September 22 , 2009 . 
