Three days before the game's event, the fictional Varrigan City became a target for a group of terrorists called "The Organizers", who severed the island city's transportation and communication ties with the rest of the world, and then released a virus onto its population that would kill them in less than 24 hours. However, the Organizers informed the populace that any person that killed another would receive the vaccine. The city was quickly transformed into the stage of a recurring game show called "DeathWatch", with announcers Howard "Buckshot" Holmes and former DeathWatch fighter Kreese Kreeley. The remaining citizens of Varrigan City as well as new hopefuls become the show's contestants, hoping to become the top-ranked fighter in the game and win a large cash prize.
Jack Cayman, a man with a retractable chainsaw built onto one arm, enters the games and manages to gain sponsorship from "Agent XIII". The game's organizers, led by Noa, knows Jack's motive is more than just to win, and learn that Jack works with someone on the outside. They come to learn that Jack was a former marine, police officer, and rogue agent, but now seems intent on a mission. Noa surmises that Jack is after the mayor's daughter, who is still inside the city.
While they could kill Jack at any time they realize he became an audience favorite thus gaining many sponsors with viewers betting on his success. They ultimately try to kill him in combat.
The player takes control of a character named Jack Cayman and must progress through levels in a linear fashion during the first playthrough, but can revisit any completed level to attempt to score more points or take on a harder challenge. MadWorld is divided into several levels representing different parts of Jefferson Island that have been converted into sets for the game show "DeathWatch", the plot is similar in setup to the manga known as Deadman Wonderland.
Most levels are open environments, allowing the player to explore them freely, although some sections of the level may require the player to earn a number of points before it will be accessible. A few levels feature motorcycle-based combat where the main character, Jack, is assaulted by foes as they race down a track or in a small arena. The player is challenged to beat the level's boss within a time limit, but in order to activate the boss fight, the player must accumulate enough points by defeating regular foes on the level.
There will also be other challenges, bonuses, or mini-bosses that will become active after the player accumulates enough points. A common feature of each of these levels is the "Bloodbath Challenge", a time-limited minigame that rewards the player for completing a specific type of activity with additional points. For example, the player may need to attempt to swing a bat at foes to knock them into a giant dartboard to score points, or to ensure foes are trapped in front of a speeding train.
Outside of these challenges, the player is awarded points for every defeat of a foe. The amount of points for beating foes increases by increasing the foe's power or using more unusual methods of winning. For example, while the player could throw an enemy on a wall, the player will earn significantly more points if they had previously forced a tire around the enemy.The player controls Jack from a third-person perspective using the Wii Remote and Nunchuk attachment for attacks and movement, respectively. MadWorld does not make use of the Wii Remote's infrared sensor, as its developers found it unnecessary to pinpoint movements on the screen in order to attack. When certain special attacks are possible, the player is prompted to press a button or move the controllers in a specific fashion to complete the action. In boss fights, the player must trigger special finishing moves that engage their foe in a series of quick time events in order to weaken, dismember attached weapons or defeat the boss, called Power Struggles. These are also possible against certain normal enemies.
The game features extreme, over-the-top violence, but designer Shigenori Nishikawa intends it to be seen in a comical light despite the dark tone of the game. For example, in a minigame called "Man Darts", players must hit enemies onto a giant dart board with a baseball bat to score points.
MadWorld features highly stylized graphics that use a limited color palette of high contrast black and white with red, partially inspired by Frank Miller's Sin City graphic novels.
MadWorld was created by Platinum Games in their attempt to make a game that would be "fun and attractive" for the Wii, but that would also have a high level of violence that would make it unique among other games. Their aim was to make use of a simpler and more elegant art style, leading them to develop the black-and-white scheme. However, this choice was not due to any limitations of the Wii's hardware, according to producer Atsushi Inaba. The black-and-white motif ultimately lead to the graphic novel-type approach used in them; both Inaba and Shigenori Nishikawa acknowledged the influence of Frank Miller's Sin City into the work, but also noted they borrowed from both Western and Japanese comic book styles to create a unique style.
The game was developed using Softimage for creation of the game's art, and a custom engine built to handle the art aesthetic and limitations of the Wii's memory. The game's sets are completely modeled with complex lighting features, but only normal maps are used to draw the game, avoiding the high-processing costs of light maps or layered textures. This also allowed the game's artists to have finer control of visibility and color balance in the game. Though the developers attempted to add reflection mapping into the game, they found it did not fit well with the comic-book style and dropped it.
Explosions and other effects, normally created in other games using particle effects to achieve a factor of realism, were also modeled with particles in MadWorld, but using specially-designed images to retain the comic book style. To overcome the lighting issues, the main character of Jack was modeled with two different textures, one used when he was in a bright area, and second used in dark areas that highlighted the main lines of the character's face. Jack and other principal characters from the game were redesigned with the black-and-white features adjusted numerous times to make sure they did not simply blend into the background as the lesser enemies in the game.
Other characters were drawn and modeled to be as destructible as possible, with numerous versions of each character having missing limbs or other bodily harm. These were put together in 2000-frame animations that were then motion-captured; movement from one animation to another was blended out with the use of Hermite interpolation. Blood spurts from each of the methods that Jack could use to kill a foe were each uniquely modeled to capture the appropriate trajectory for the type of injury, and often increasing the realistic amount of blood in order to make it stand out in the world. The spatters of blood on the walls, floor, and other characters was also modeled within the game using a collision detection system and a complex system for how the blood would interact with Jack's clothing.
Early builds of the game resulted in disorientation and eye strain due to the lack of colors. To avoid this, the developers limited the amount of on-screen movement and adjusted the game's textures to include more gradual changes from black to white. While some of MadWorld relies on the Havok engine for modeling physical interactions in the game, the developers found they had to resort to their own programs to capture some of the reactions and behaviors of the enemies for many of the unique killing methods.
Comparisons have also been drawn between the game and Inaba's last project, God Hand, a comedy beat 'em up for the PlayStation 2. However, Inaba claims that while God Hand was developed for "hardcore" gamers, MadWorld is "a lot easier to pick up." The game's use of over-the-top violence was intentional to add humor to it.
The game's story was written by Yasumi Matsuno, famous for his design in the Ogre Battle series and a number of Square Enix titles. Matsuno was given two opposing guidelines to writing the scenario. While the development team ruled that violence should acceptable in the game's world, Inaba expressed his desire for violence to be "denied in the end" due to current views of violence in the video game industry.
Matsuno combined the ideas for MadWorld's DeathWatch gameshow environment: violence is both accepted and required within the show, but not outside of it.
Proops and DiMaggio, who had previously worked together on animated films such as Asterix and the Vikings and Kaena: The Prophecy, were both contacted by the voice cast director Jack Fletcher to play the parts of the announcers for the North American and European release. While most of their lines were already scripted, the two were able to ad-lib during recording, with some lines being retained in the final game.
MadWorld has received generally positive reviews from critics. In its April 2009 issue, Nintendo Power gave MadWorld a 9/10 rating. IGN gave the game a 9.0/10, praising the style, gameplay, and music, but criticizing the camera and short length, though it mentions that the hard difficulty level lengthens the game and increases the challenge considerably. Pixel Hunt called it "one of the few must-have Wii titles". StageSelect.com praised the title for its artistic game design, but stated that the overall delivery had trouble living up to the hype.
About.com felt the game was more flash than substance, giving it a 3/5 and stating that, "Divorced of its unique graphics and over-the-top presentation, this is actually a rather mediocre beat-em-up." Game Informer disagreed, praising the deep combat system and arguing that "for an amateur to become a talented executioner, you'll have to lash out creatively, prolonging your victim's death through multiple phases of pain. MadWorld runs the gamut in violence, taking an encyclopedic approach to its variety in kills. Some of the bloodletting will make you squirm uncomfortably." IGN opined that "MadWorld does not place emphasis on style over gameplay...there's plenty of fun, smart mechanics to back up the overwhelmingly slick look and sound of the title.
MadWorld has been the subject of controversy in the United Kingdom due to its violent subject matter. John Beyer, director of mediawatch-uk, has expressed his distaste over the game's content, stating his desire for it to not receive a rating from the BBFC, which would effectively ban it from being sold. He stated "We need to ensure that modern and civilized values take priority rather than killing and maiming people." Fans' response to the organization have been hostile, accusing mediawatch-uk of being "cowards" and "narrow-minded bigots."
On August 19, 2008, Sega announced that MadWorld would not be released in Germany. Despite the fact that Australia is also known for strict video game classification, the game was released there unedited, with an MA15+ rating.
One Nintendo representative has said that the Wii is a system for anybody, including adults, and that the game, like all video games, would be rated and would therefore be available for purchase to people of and above that age rating. In a preview, Eurogamer commented: "It's difficult to understand why there's so much controversy surrounding MadWorld when the violence is so very Tom and Jerry... It really is hard to be offended... because it's just so ridiculous."
On March 10, the National Institute on Media and the Family issued a press release expressing its disappointment in Nintendo for allowing MadWorld to be released on the Wii.