 Bungie kept the public informed on game development via weekly updates on their web site . During development , the game was divided into single player and multiplayer builds ; this made debugging and testing the much smaller multiplayer files quicker . While details of Halo 3 's multiplayer were widely disseminated in the sixteen months leading up to the release , the single @-@ player aspect of the storyline was kept relatively secret throughout much of the development to build up interest . The first campaign screenshots did not appear until a year after the announcement trailer , on July 5 , 2007 , as a " tease " for the planned pace of marketing . 
