Halo: Combat Evolved

Halo: Combat Evolved is a first-person shooter video game. It starts the game series called Halo. It came out in 2001 for Xbox and was released on the personal computer later. It became very popular and has made a lot of money. Many people say it is the Xbox's "killer app", which means the best program for a system. Because it was liked by so many people, there have even been 6 books and a Graphic Novel written about it. Halo is rated M for mature.
Story
Setting
The game setting is on or around a giant ring-shaped structure in space. The ring has plants and animals that live on it. It is very old and was made long ago by a civilization called the "Forerunners." In the game, the year is 2552. In the storyline, humans have created faster than light travel, and now live on many planets and moons in and out of the Solar System, both fictional and real. In the year 2525, humans living on a planet around another star met several alien species. They are grouped together and known as the Covenant. The Covenant declared religious war on the humans.
The game starts with a ship, The Pillar of Autumn. It arrives at Halo, surrounded by many Covenant Ships.
Plot
Warning: Spoilers*
Master Chief is the last super soldier who is able to fight on the Pillar of Autumn. The Pillar of Autumn jumped (teleported) from the planet Reach. Reach was being destroyed, so they escaped. The ship is piloted by Captain Keyes. The ship arrives in front of Halo. Halo is surrounded by many Covenant ships. The Covenant board the Pillar of Autumn to kill the humans. Keyes orders the Master Chief (who is sleeping while frozen) to be awakened. After putting Cortana (an Artificial Intelligence) in his head, the Master Chief escapes in a lifepod with other Marines. He did this on order by Captain Keyes, who knew they could not win. Captain Keyes decides to crash his ship onto Halo, before it is completely destroyed by the Covenant. The Master Chief rescues as many Marines as he can. Cortana discovers Captain Keyes is still alive. Master Chief goes to rescue him from a Covenant Ship. They escape with the Captain and more Marines. They find a map-room to find the control room for Halo. They want to stop the Covenant from using Halo, because it is a weapon. The Master Chief fights through many aliens to the Control Room. He puts Cortana into the data. She discovers something terrible and tells the Master Chief to find Captain Keyes. Captain Keyes went with several Marines to destroy a take or destroy a supply of Covenant Weapons. The Master Chief discovers the Captain was attacked by a different enemy. They are called the Flood. The Flood are a species of parasite, which can infect bodies and turn them into Combat Forms (which are fast zombies that can use weapons). He finds a flying machine that protects Halo. It is named 343 Guilty Spark. It explains that he should turn on Halo's weapons to destroy the Flood. The Flood want to escape Halo and infect other species. The Master Chief must get an Index to do activate Halo. The Master Chief gets the Index (which can activate Halo's weapons).
They both go to the ring's control room to activate its weapons. Surprisingly, they find Cortana that tells to the Chief that the ring can not destroy the Flood. It destroys the food of the Flood. This means humans, Covenant and all other suitable living species. Following Cortana's suggestions, Master Chief goes to the Pillar of Autumn. As he destroys the core of the ship, he escapes. He uses a human spaceship to get into space while the explosion destroys Halo.
Characters
The main character in the game is Master Chief. It is the character the player controls in the game. Other main characters are Cortana and 343 Guilty Spark, the two machines. Apart from them, other human characters appear who fight in the side of the player against the aliens and the flood. The most notable are Sergeant Johnson and Captain Keyes.
In the first Halo game, there are no alien characters who play an important role in the game. However, in the next two halo games, Halo 2 and Halo 3, many important alien characters appear.