Halo Combat Evolved (Microsoft Xbox, 2001)

Halo is a futuristic first-person shooter that casts you in the role of a genetically enhanced super-soldier known only by his rank, Master Chief. The game includes a ten-level campaign playable on four difficulty settings and three multiplayer options: two-player cooperative, four-player competitive via split-screen display, and four-player competitive via System Link. Notable features include rechargeable energy shields, allowing soldiers to quickly recover from enemy damage, and the ability to drive or pilot four types of vehicles. Master Chief will also be able to use ten types of weapons on the battlefield, from assault rifles and rocket launchers to plasma grenades and shotguns.

In the most obvious sense, the "Halo" is a space station built in the shape of an enormous rotating wheel. As the wheel spins, it creates centrifugal force that mimics gravity on its inner rim. An entire world exists inside this wheel, with huge developed structures and vast, open landscapes. But something else exists in the Halo as well -- something mysterious and powerful. All that is really known is that a force of alien invaders is desperate to find it and they are leaving death and destruction in the wake of their search. This mystery of Halo must be solved and the aliens must be vanquished, before they find what they are looking for and destroy us all.

Some of the basic themes and plot points in Halo may be familiar to gamers who have played Marathon, Bungie's successful first-person shooter which was released in 1992 for the Macintosh platform. Among other elements, Marathon is known for intelligent level design and a deep, intriguing story. Though Halo should not be considered a sequel to Marathon, the two share common plot elements and have related back-stories. Initial development of Halo was done simultaneously for the Macintosh, the PC, and the Xbox.