Halo: Combat Evolved is about the Human race and its stuggle against the Covenant, a religious driven technologically advances race and the Flood, and organism that enters the dead and reinvents their bodies for its purpose. "Spartans" are men fitted in full body armor suits outfitted with the best technoology the humans have.
Spartans were created for one purpose. To end the Convenant and Flood and to save humanity. Master Chief is the head of the Spartans and the only one to still exist. It is up to him to save humanity and bring the world back together. The story is presented through an instruction manual, scripted events and conversations during the game, and in-game cut-scenes. The game begins as the Pillar of Autumn exits slip-space near a mysterious ring-shaped space station, called "Halo" by the Covenant. A Covenant fleet attacks and heavily damages the Pillar of Autumn. Keyes initiates "The Cole Protocol", a procedure designed to prevent the Covenant from learning the location of Earth. While Keyes prepares to land the ship on Halo, the Master Chief and Cortana escape via an escape pod, which crash lands on the ring. Cortana and the Chief are the only ones that survived the impact of the escape pod crash.
On its release in 2001 Halo broke saled records, priced at $49.99 by 2005 Halo: Combat Evolved sold 5 million copies. The game recieved close to perfects by every gaming critic, for its state of the art graphics, gameplay, orignal storyline, characters, voice acting ect. Halo brought friends from all over together, to unite as a team and fight a common enemy. It changed First Person Shooter games forever bringing a different kind of combat to the game it was the first to bring multiplayer to a game and make it successful. And that is why this game has changed a generation.