Last week, however, Microsoft confirmed that the Xbox 360 shooter will in fact sell for $60--with a $100 collector's bundle packing an exclusive ODST-themed wireless Xbox 360 controller--when it launches on September 22.

Explaining the higher-than-expected cost of the game, Microsoft told Joystiq:

At the time of those statements, the overall scope of Halo 3: ODST was not yet finalized, and since then the project has grown increasingly more ambitious. We believe this standalone experience is much more than just an expansion. Halo 3: ODST provides a new campaign from the point of view of an entirely new character. Combine that with three new multiplayer maps, the entirely new cooperative mode called Firefight, and the complete Halo 3 multiplayer collection on a standalone disc, we feel this is a good value and tremendous addition to the Halo franchise.

That Firefight mode Microsoft mentions sees up to four players facing off against "increasingly challenging waves of enemies," similar to Gears of War 2's Horde mode. Meanwhile, the game's single-player component has players exploring an open-world rendition of New Mombasa and reliving the experiences of missing comrades.

Along with the above, Halo 3: ODST will also pack multiplayer beta access to Bungie's next Halo game on the Xbox 360, Halo: Reach, of which almost nothing is known.