One of the biggest gameplay additions in Halo 3: ODST is Firefight mode, a cooperative multiplayer match in which players must fend off successive waves of enemies. Bungie says it could end up in Halo: Reach as well.

"I can't talk too much about Reach specifics, but hopefully the game mode's going to be received as well we think it will be, and people are going to enjoy it," Bungie community manager Brian Jarrard told Eurogamer. "I don't think we've ever been known to really take things away from each successive release, so I think it's safe to say that if Firefight gets a lot of traction and people love it, it probably has a good future home in our next title as well."

Halo 3: ODST is set to arrive on September 22nd. Halo: Reach is slated for a late 2010 release.