Resident Evil Zero

Resident Evil Zero, known in Japan as Biohazard 0 (バイオハザード0), is a survival horror game that was developed and published by Capcom for the Nintendo GameCube and released in. It was the last of the main titles to use the original Resident Evil game system prior to the change in system ushered in by the release of Resident Evil 4.

The game's storyline serves as a prequel to Resident Evil, covering Rebecca Chambers' ordeal a day prior. The game was released on November 10, 2002 in North America, November 21, 2002 in Japan, February 28, 2003 in Australia and March 7, 2003 in Europe.

Gameplay
The main gameplay feature of Resident Evil Zero, dubbed the "partner zapping" system, is unique in the series in that instead of choosing a single character to play through the whole game, the player controls both the main characters, Rebecca Chambers, STARS Bravo team's medic, from Resident Evil and Billy Coen, an escaped ex-military convict, through the entire game. Both characters can travel together, with one character being controlled by the player and other by the computer, or split up and search separate areas each at the same time. This dual control is central to solving some of the puzzles in the game. The difference between the characters is that Rebecca can acquire chemicals with her mixing kit and can get into tight spaces, but has less health. In contrast, Billy can handle heavy objects, has a lighter and can sustain more damage than Rebecca, but cannot mix herbs.

The game also does away with the use of boxes placed in fixed locations for the player to store items in. Instead, the player can now drop items on the floor to make room for new ones, which they can later retrieve for future use. The locations of dropped items are displayed on the player's map.

Plot
On July 23, 1998, STARS Bravo team is sent in to investigate a series of grisly murders in the Arklay Mountains region outside of Raccoon City. On the way to the scene, Bravo's helicopter malfunctions and is forced to crash land in the forest. The team soon discover an overturned military police transport truck, along with the mutilated corpses of two officers. The team split up and Bravo team's field medic, Rebecca Chambers, finds a train stopped in the middle of the forest; the Ecliptic Express.

Soon after, she discovers that it is infested with zombies. After a little exploration, she teams up with the man the military police were escorting to his execution; former Marine Billy Coen and the two explore the remaining train compartments whilst combating the zombies, swarms of strange leeches, and a mutated scorpion.

As the train begins speeding out of control towards a cliff, the two manage to apply the brakes and divert its course towards an abandoned research and training center. They investigate the underground facility, being forced to defeat the Umbrella Corporation's experiments; mutated insects, spiders and primates. During their navigation, Coen reveals that his unit was forced to kill the innocent civilians of an African village in the midst of a civil war against his wishes, and he soon found that their actions were based on false information.

They discover that the former operator of the facility James Marcus, along with Ozwell E. Spencer and Edward Ashford, discovered the Progenitor virus which, when combined with the ebola virus, created a strain that, despite being photosensitive, caused rapid mutations. Ashford originally wanted to use the virus to help the handicapped through its regenerative effects, but after his death Spencer and Marcus began research on its applications for bio-weapons, combining it with leech DNA which eventually led to the formation of the t-virus. After a showdown with a gigantic bat inside a church, Coen is attacked by a t-virus infected primate and becomes lost inside an underground laboratory. While searching for him, Chambers meets Enrico Marini and fights a released Tyrant before finding Coen washed up on a walkway. After fighting the Tyrant together, the two eventually meet Marcus. It is revealed that both Wesker and William Birkin were oblivious to the cause of the outbreak in both the Ecliptic Express and the mansion, and that the real culprit was Marcus, an employee of Umbrella who operated the facility until his assassination by Wesker and Birkin, on the orders of Spencer. During his dying moments, his pet queen leech entered his body and reproduced exponentially over ten years to absorb his DNA and memories to bring him back to life. Marcus proceeds to split into a mass of leeches, before chasing Chambers and Coen through the facility.

Birkin activates the self-destruct system as the Queen Leech, Chambers, and Coen continue to fight. After being injured due to a brief exposure to sunlight, the monster is paralysed when the overhead entrance to the laboratory is opened just as the sun rises. Chambers throws Coen a revolver and he delivers the final shot to the Queen Leech.

As the facility crumbles, the two escape into the forest and come to a halt on a cliff overlooking the Spencer estate. They salute one another after Chambers declares Coen "officially dead". Each goes their own way, with Chambers heading towards the mansion to investigate the whereabouts of Bravo team.

Development
Zero was first unveiled during the Tokyo Game Show in 2000. The game was originally slated for the Nintendo 64, as it was believed by the developers that the platform's cartridge-based media would be more capable in handling the item dropping and 'partner zapping' systems proposed for the game than the disc-based media used by the PlayStation and Dreamcast, due to the lack of loading times. However, production of the game shifted from the Nintendo 64 to the GameCube as a result of the transition to sixth generation consoles. Since the GameCube made use of a disc-based media, the programmers were forced to rely on clever programming methods to shorten the loading times.

In contrast to other Resident Evil prototypes, which have been known to go through massive changes during production, the story and settings remained mostly unchanged in the released version. Rebecca's original character design featured her wearing a beret instead of the red bandanna she wears in the original game. In the released GameCube version, she uses the same design from the previously released GameCube remake of Resident Evil.

Reception
The game has sold 1.25 million copies worldwide.

Wii version
A Wii version of Resident Evil Zero was released in Japan on July 10, 2008 as "Resident Evil Archives: Resident Evil 0". The Wii version is a direct port of the original GameCube game with added support for the Wii Remote and Nunchuk (without pointer controls), Classic Controller, or the GameCube Controller. It was also released in North America on December 1, 2009. IGN gave the Wii version a "poor" 4.5/10.

Novelization
Zero Hour is a novelization of the game written by S. D. Perry. It is the seventh and final Resident Evil novel written by Perry, but precedes the others in chronological order. It follows the same continuity as Perry's previous novels based on the series.