Halo: Combat Evolved is a first-person shooter, that focusing on combat in a 3D environment, and taking place almost entirely from a character's eye view. The player can move around and look up, down, left or right. The game features vehicles, ranging from armored jeeps (Warthog) to tanks (Scorpion), alien hovercraft (Ghost) and even an aircraft (Banshee), all of which can be controlled by the player. The game switches to the third-person perspective during vehicle use for pilots and mounted gun operators; passengers maintain a first-person view.
The player character is equipped with a damage-absorbing energy shield, in addition to hit points. The shield's charge appears as a blue bar in the upper-right hand corner of the game's heads-up display. When the shield is fully depleted, the player is highly vulnerable, and further damage reduces the character's health level. Critically, however, the shield will recharge if no further damage is sustained for a brief period.
Halo's arsenal consists of weapons from science fiction. The game has been praised for giving each weapon a unique purpose, thus making them useful in different scenarios. For example, plasma weapons need time to cool if fired too rapidly, but require no reloading. Instead, players are forced to discard them after depleting their batteries. In contrast, conventional firearms cannot overheat, but require reloading and ammunition. All weapons may be used to bludgeon enemies, which allows a player to silently kill opponents without alerting other nearby enemies. Players may carry only two weapons at once; thus, a strategy is required when using and selecting firearms.
The player can carry up to eight grenades at a time: four fragmentation and four plasma grenades each. Like the game's other weapons, the two types of grenades differ; the fragmentation grenade bounces and detonates quickly, whereas the plasma grenade adheres to targets and takes longer to detonate. A controller button assigned to grenades eliminates the need to holster firearms before throwing.
Combatants
The game's main enemy force is the Covenant, an alliance of alien species. Their forces include Elites, fierce warriors protected by recharging energy shields much like the player's own; Grunts, which are short, cowardly creatures, usually led by Elites, and who often flee in terror instead of fighting unless an Elite is present; Jackals, which have highly durable energy shields attached to their arms; and Hunters, large, powerful creatures with thick armor plates that cover the majority of their bodies.
A secondary enemy is The Flood, a parasitic alien life form that appears in three main variants. Infection Forms, the true form of the Flood, are fragile, but often travel in swarms; they do little damage individually, but the swarms often number in the hundreds. Combat Forms result from humans and Covenant Elites who are infected by Infection Forms, and have hideously deformed bodies. Bloated Carrier Forms serve as incubators for new Infection Forms, and when wounded or near a potential victim, they explode to damage other nearby life forms and to release their spores. Battling the Flood, Covenant and player are the Sentinels, robotic drones designed by an extinct race called the Forerunners. Sentinels lack durability, but use powerful beam weapons and are immune to infection by the Flood.
The artificial intelligence in Halo has been favorably received. Enemies take cover and use suppressive fire and grenades. Some enemies retreat when their superiors are killed. The player is often aided by United Nations Space Command (UNSC) Marines, who offer ground support, such as manning gun turrets or riding shotgun while the player is driving a vehicle.
Synopsis
Setting
Halo takes place in a science fiction universe created by Bungie Studios specifically for the game. According to the story, the overpopulation of Earth and the realization of faster-than-light travel have caused the human race to colonize other planets. A keystone of these efforts is the planet Reach, an interstellar naval yard and a hub of scientific and military activity. A secret military endeavor, dubbed the SPARTAN Project, was established on Reach to create an army of biologically-engineered, cyborg "super-soldiers". Thirty-two years before the beginning of the game, a technologically advanced collective of alien races, the Covenant, began to attack human settlements, declaring humanity an affront to their gods. The United Nations Space Command experienced a series of crushing defeats, and, although the super-soldiers of the SPARTAN-II Project fought effectively against the Covenant, they were unable to turn the tides of war.
To prepare for a mission to discover the location of the Covenant's homeworld, SPARTAN-II soldiers were recalled to Reach for further augmentation. Two days before the mission was to begin, Covenant forces attacked Reach and destroyed the colony. A starship, the Pillar of Autumn, survived the onslaught with the lead Spartan II, Master Chief, onboard. The ship initiated a random jump to slip space (similar to hyperspace), hoping to lead the enemy away from Earth. The game starts with the Pillar of Autumn encountering Halo.
The titular Halo is an enormous, ring-shaped artificial space habitat/planet, which (according to Bungie Studios) has a diameter of ten thousand kilometers. Halo sits at a Lagrange point between a planet and its moon. Centrifugal force created by the rotation of the station provides the ring's gravity.
Characters
The player character is Master Chief Petty Officer John-117, one of the few (see Halo: The Fall of Reach and its sequels for more information) surviving super-soldiers of the SPARTAN-II project, and the main character of the story. Accompanying the Master Chief is the Pillar of Autumn's feminine artificial intelligence construct, Cortana, who resides in a neural implant connected to his battle armor, codenamed MJOLNIR Mark V. The Pillar of Autumn's captain, Jacob Keyes, is also a major character. Playing an mainly antagonistic role in the game's events is 343 Guilty Spark, an eccentric artificial intelligence responsible for monitoring and maintaining Halo's systems.
Plot
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 enemy of the game, The Covenant. A Covenant fleet attacks and heavily damages the Pillar of Autumn. Jacob 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.
Keyes survives the Autumn's crash landing, but is captured by the Covenant. In the second and third levels of the game, the Master Chief and Cortana gather human survivors and rescue Captain Keyes, who is imprisoned on the Covenant ship Truth and Reconciliation. Once rescued, Keyes orders the Master Chief to beat the Covenant to Halo's control center and to discover its purpose. The Master Chief and Cortana travel to a map room called the Silent Cartographer, which leads them to the control room. There, Cortana enters the systems and, discovering something urgent, suddenly sends the Master Chief to find Captain Keyes, while she stays behind. While searching for his commander, the Master Chief learns that the Covenant have accidentally released the Flood, a parasitic alien race capable of spreading itself by overwhelming and infesting other sentient life-forms. Keyes falls victim to them while looking for a cache of weapons. The release of the Flood prompts 343 Guilty Spark to recruit the Master Chief in retrieving the Index, a device that will activate Halo and prevent the Flood from spreading beyond the facility.
After the Master Chief retrieves and begins to use the Index, Cortana re-appears and warns him against the activation. She has discovered that Halo's defense system is a weapon designed to kill all sentient life in the galaxy, which the Flood need to spread. When confronted with this information, 343 Guilty Spark states that the installation technically only has a maximum radius of twenty-five thousand light-years, but that its pulse would trigger other similar installations as well, killing all sentient life in the galaxy.
While fighting the Flood, the Covenant, and Guilty Spark's Sentinels, the Master Chief and Cortana attempt to destroy Halo before 343 Guilty Spark activates it. Cortana discovers that the best way to destroy Halo is to cause the crashed Pillar of Autumn to self-destruct. However, Captain Keyes' authorization is required to destroy the ship. By the time that they reach Keyes, he has been infected and turned into a Brain Flood. The Master Chief retrieves Keyes' neural implants directly from his brain, and Cortana activates the Autumn's self-destruct sequence. However, 343 Guilty Spark reappears and deactivates the countdown, discovering the record of human history in the process. The Master Chief manually causes the Pillar of Autumn's fusion reactors to begin to melt down, and the Master Chief and Cortana narrowly escape the destruction of the ring via a fighter.
