With 2 spinoff games, multiple novels and an expanding range of figurines planned, gamers are starting to fear that Halo may face the fate of Medal Of Honor and Command &Conquer series.
But Microsoft insists that its strategy is to "explore not exploit" the Halo universe.
"The Halo universe is really, really big now," said Frank O'Connor, Microsoft Games content manger. "Literally the Halo games have only covered one year; a couple of months within a year in fact. "
"We have a really detailed story bible, we do really have it all planned out. There are so many areas of the universe to explore; the real challenge is picking which is the most exciting area for people. Is it UNSC Marines fighting alongside Spartans against the Covenant? Or is it what happens next after Master Chief's appearance in Halo 3?"
"We have a well defined, carefully orchestrated, properly planned universe to explore not exploit," he added. "And that's the tricky part: what are the things people want to do? We have to pick things that people want. That's what you see with the range of McFarlane toys - people want their armour permutation."
