Scooby-Doo! Mystery Mayhem

'Scooby-Doo! Mystery Mayhem' is a video game based on the Hanna-Barbera/Warner Bros. cartoon Scooby-Doo. The game was released by Artificial Mind and Movement, THQ and Warner Bros. in 2004.

Plot
Mystery Inc. is called by Alan Dinsdale, librarian of the Hambridge University Library and old friend of Velma's. Dinsdale explains that real ghosts and shadows have started appearing have scared people away. The gang also meet Walter Peabody, Alan's assistant and the book restorator, who claims that the key to the basement has gone missing. While searching the library, Shaggy and Scooby discover a photograph of a young Dinsdale in Washington D.C., and a telegram to Peabody from someone with the initials "S.D.". They later spot a strange white ghost opening a door in the back in which they discover is a way to the basement. The duo eventually come across the white ghost's hideout that withholds a strange book and a receipt from a book binding shop, when suddenly a ghost enters the room and gets devoured by the book. After collecting the evidence, the duo plan to show it to the others.

The duo come across Velma who lost her glasses after following the white ghost. After they find her glasses they show her the magic book in which she says it's a grim-war with the power to release and capture spirits and also pages are missing from it. She explains that they can capture the ghosts in the library as the book only contains the ghost page. Along the way, Shaggy and Scooby find the shadow page, allowing them to capture shadows too. The duo begin fighting their way back to the where they started where they show the others the magic book. Dinsdale tells them that the book is called the Tome of Doom which frightens Shaggy and Scooby. Strangely, there's another Tome of Doom in a nearby display case that Velma deduces is fake. She also examines the receipt Shaggy and Scooby found which proves her point. Shaggy sees the white ghost, and he and Scooby chase after him. The white ghost pushes a bookshelf that moves like a secret door and separates Shaggy from Scooby. After he finds Shaggy they begin fighting the ghosts in the room. After that, the fake ghost gets chased by a real ghost which allows the duo to capture him. The gang is confused why the ghost didn't get pulled into the book until Velma believes that he isn't a ghost at all. He is revealed to be Peabody who didn't want anyone to know that he made a fake Tome of Doom while he tried to steal the real one. However, it's unknown what was Peabody's motive or why he ripped out pages from the Tome of Doom. Walter is arrested, and the group is called by famous filmmakers the Milton Brothers, who are also having problems with the supernatural. Dinsdale allows Velma to borrow the Tome of Doom for further analysis, but as the gang leaves the library, a mysterious woman watches them.

The group arrives at the Milton Brothers Movie Studio, where they are greeted by Doug and Earl Milton after a well groomed man leaves. The brothers explain that the man was Robert Zabrinski, a businessman who has been trying to buy the studio for his real estate company Greenwood Development. Shaggy and Scooby make their way through Studio A where they find the poltergeist page in an electrical room. After capturing the poltergeists in the room, a red knight kidnaps Scooby. Shaggy chases him and sees him going into Studio B and Velma and Earl show up, both having seen the red knight. Shaggy reveals the situation to them and plans to rescue Scooby, with Earl tagging along to film Shaggy's heroics. He goes into the studio and finds Scooby and Daphne locked in cages and Daphne sees a crane the he can use to lift up Scooby's cage. Shaggy discovers a fuse and gear are missing and goes to find them. He also finds a brochure for the Gold Mountain Western Theme Park. He locates the pieces, as well as the mummy page. After repairing the crane he frees Scooby but the red night attacks them, but they manage to use a catapult to send him flying and he escapes, leaving his helmet behind and the duo find it. After they free Daphne and capture the remaining monsters in Studio, the duo reunites with the group and Earl outside where they reveal the helmet and the recovered Tome of Doom pages. Velma realizes that there's a link to the library case based on the recovered pages. The group sets up a trap for the red knight (now covering his head with a box), and after a lengthy chase, Shaggy and Scooby lure him in and capture him in a net. The knight is unmasked as Zabrinski, who had received the poltergeist and mummy page from Peabody to scare away the Milton Brothers and buy their studio. Doug is also found tied up in a mummy costume and thanks the gang by letting them be part of a new film.

Meanwhile, at a secret headquarters, the woman from the library case receives word that Zabrinski has been arrested and Peabody hasn't revealed anything to the authorities. A mysterious figure decides to move on with "the plan". The group travel to the Gold Mountain Western Theme Park to investigate more monsters there, as Zabrinski was also trying to buy the park based on the recovered brochure. They meet Johnny Channayakpatra, owner of the park, and Mindi Stiles, the only employee left working. Shaggy and Scooby investigate the hotel and after an eating contest between the two, Shaggy falls through the floor. After encountering a mysterious woman in the hallway, Scooby finds Shaggy in the basement. They exit through the basement and find a photograph of Zabrinski with a dancer in a saloon, and encounter dust devils on Main Street. They also encounter Fred who got locked in a jail cell by a mysterious woman. After rescuing Fred, they discover a safe in the bank and realize someone hid something important in it. The duo later investigate a mine cart ride and find food in a mine cart and begin eating until a woman starts the ride that takes them into the tunnel. After surviving the ride, they exit the mine and enter the school where they discover a surveillance system, some costumes that match the woman from the hotel and the saloon dancer, as well as the combination to the safe. Inside the safe is the dust devil page. After defeating the dust devils, they head to the hotel where they find a giant dust devil spinning a carousel at a rapid speed with Fred, Daphne, and Channayapatra on it. Shaggy and Scooby eventually capture the monster as it spews out a woman dressed as an Indian. They unmask the Indian as Mindi, who is revealed to be a spy for Greenwood Development based on documents Velma found and is arrested.

After a period of time, the gang head to mansion in the middle of a swamp. Velma explains that the area is haunted by zombies and scared away everyone in the area, which allowed Greenwood Development to buy it. Upon arrival, the gang notice someone placed a giant antenna on the roof of the mansion, and the mansion itself appears abandoned. When gang splits up, Shaggy and Scooby witness Fred and Daphne get captured by army soldiers with fear-inducing laser guns and run away upon getting spotted. While running, Shaggy gets separated from Scooby and ends up covered in mud and running into a tree. Eventually, the dizzy Shaggy is captured and mistook for a zombie, and is caged with all the other zombies. Scooby meets Billy Bob, a young native who helps him rescue Shaggy, but their rescue results in all the zombies escaping. After the trio escape by motorbike, Billy Bob reveals to Shaggy and Scooby that after the zombies forced him to vacate, Greenwood Development ordered the military to send the zombies away. Velma arrives and reveals that zombies have left the soldiers defenseless and are attacking Fred and Daphne. Luckily, Billy Bob reveals he found the zombie page in one of the military trucks, allowing Shaggy and Scooby to capture the zombies and a giant zombie. Once Fred and Daphne are rescued, the military prepare to arrest them for trespassing until they tell them their investigating motives. The leader of the soldiers Sgt. Jeremy Rhodes, explains to the gang that they were ordered by Greenwood Development to clear the area of zombies before it was sold to Sherman-Tech, a scientific research and experimental institute that owns Greenwood Development based on the documents Velma previously found. The gang theorize that the people of Sherman-Tech buy and sell land to themselves after scaring away the owners. Rhodes also reveals he was ordered to bring the zombies to Sherman-Tech Headquarters and suggests that they go there to find answers.

Velma deduces that Sherman-Tech's plot involves the giant antennas that are placed in the areas bought by Greenwood Development. Fred books a tour at Sherman-Tech Headquarters where the gang meets Travis Sherman, founder of Sherman-Tech, and his chief executive officer Selena Drake, who is revealed to be S.D.. While Fred, Velma, and Daphne take the tour, Shaggy and Scooby sneak off and infiltrate the laborious institute. Later, they reunite with the others but Sherman and Selena reveal that they've mind-controlled Fred, Daphne, and Velma with a prototype antenna. Sherman explains that they have built transmitters all over the United States in their areas purchased from Greenwood Development to brainwash all humans to buy Sherman-Tech products and destroy their competition. Drake attempts to mind-control the duo, but their simple minds allow them to be immune. As an alternative, Sherman orders Fred, Daphne, and Velma to kill them. Fortunately, Shaggy and Scooby manage to disable the machine, releasing Fred, Velma and Daphne from its control.

Angered, Sherman orders several scientists to seize the gang, but they refuse. They reveal themselves to be undercover FBI agents, revealing that Alan is one too, much to Velma's surprise. Dinsdale explains that they have suspected Sherman's scheme for months but couldn't get a lead and let Mystery Inc. find the evidence against Sherman and secretly followed them throughout their journey. Sherman surrenders, however, Selena snaps and evades arrest, releasing fire ghost in her path. Fortunately, fire alarm sprinklers go off and extinguish the ghosts' flame, allowing Shaggy and Scooby to capture them along with escaped zombies. The duo reunite with Fred, Daphne, Velma, Sherman, Dinsdale, and the FBI agent outside the building where they see the mentally unstable Selena on the roof, claiming she'll use the antennas for world domination. Eventually, she releases the Tome of Doom's strongest spirit, the Fire King, to destroy the group. Shaggy and Scooby distract the Fire King with a sprinkler system while Velma reverses the polarity of a nearby antenna, causing it to fire a laser to create rain clouds that extinguish the King's flame, allowing Shaggy and Scooby to capture him. Selena is captured and finally arrested.

Scooby and Shaggy are thanked by Dinsdale, who in turn gives them Scooby Snacks for their troubles. The gang and the agents all celebrate their latest case.

Gameplay
The levels are very basic: there are three main objectives: There are also collectible sandwich ingredients in each level that unlock mini-games.
 * Seal all the monsters in the level.
 * Find the five clues.
 * Complete the level and its missions.

Levels and Biological Villains
There are five levels: The Haunting of Hambridge, Mayhem at the Movies, Weird Wild West, Bad Juju In The Bayou and the hardest level, Hi-Tech Terror. The villains are (from first to fifth), Walter Peabody, Robert Zabrinski, Mindi Stiles, the fourth level does not have a biological villain, and the fifth and final villain is Selena Drake who Scooby and Shaggy chases around the hi-tech mansion-like laboratory. The costumes are a ghost, the Red Knight and a mysterious woman

Bosses

 * Fake Ghost: He tries to attack you by running into you, knocking you back a little, causing no damage, and can turn bookshelves, also causing no damage. To beat him, suck up all of the ghosts that are following his orders. After doing this, a ghost will realize that the fake ghost isn't real, and scare him off.
 * Red Knight: He chases you throughout the studio. If he touches you, you instantly loose all of your cool. To beat him, run through the studio while he keeps taking damage from the traps. After two laps, run into the castle, and the Red Knight gets captured by a giant net.
 * Giant Dust Devil: He breaks himself into smaller dust devils while launching horses from the rapidly spinning horse ride. When you suck up enough of his dust devil pawns, The last remains of him come down in one piece. In this state, he behaves like a normal dust devil, except he is bigger, faster, and takes a longer time to suck up. Once you suck him up, you win.
 * Big Zombie: At first, you have to suck up the three zombies that are terrorizing the van. After you do this, The big zombie will come down and fight you. He attacks like a regular zombie, except he can stomp on the ground and send a shock wave through it, and, like a normal zombie, can breathe on you with smelly breath. To defeat him, just keep trying to suck him up until he is finally gone.
 * Giant Fire Ghost: This is the final boss of the game. He can launch fireballs at you, and if you activate a sprinkler, he will throw a large amount of fireballs, all at one time. If there are less than two normal fire ghosts on the field, the next fire ball he throws will summon one. Your goal is to make the giant fire ghost wither away the rocks that are blocking the sprinkler, and then activate them. Once you have activated all four sprinklers, Velma will activate the rain to get rid of the giant fire ghost's fire, but the battle is not over yet. Like normal fire ghosts, the giant fire ghost turns into a normal ghost from water. In this state, he acts like a much bigger version of a regular ghost, except he follows you. All you have to do is suck him up completely, and you will have beaten the game.

Cool Meter
When something scares Scooby and Shaggy, their Cool Meter is drained. If the Cool Meter is totally drained, the next time an enemy catches Scooby or Shaggy, they will run away and have to start at their last save point. To replenish the Cool Meter, Scooby and Shaggy find Scooby Snacks.

Radar
There is a small circle representing radar. The yellow triangle in the center represents Scooby and Shaggy, red dots on the Radar are enemies, and blue dots on the Radar are bosses.

Cast

 * Scott Innes - Scooby-Doo, Shaggy
 * Frank Welker - Fred, Doug Milton, Mummy
 * Grey DeLisle - Daphne, Selena Drake, Mindi Stiles, Actress, ShermanTech Scientist
 * Mindy Cohn - Velma
 * Jeff Bennett - Alan Dinsdale, Walter Peabody, Robert Zabrinski, Travis Sherman, Mercanary
 * Tom Kenny - Earl Milton, Johnny Channayapatra, Billy Bob, Mercanary, ShermanTech Scientist
 * James Arnold Taylor - Jeremy Rhodes, Zombie, ShermanTech Scientist, Watchman, Security Guard
 * Jennifer Hale - Poltergeist, Computer Voice, ShermanTech Scientist

Reception
Mystery Mayhem was met with very mixed reception. GameRankings and Metacritic gave it a score of 53.20% and 53 out of 100 for the Game Boy Advance version; 59.82% and 56 out of 100 for the Xbox version; 59.52% and 55 out of 100 for the PlayStation 2 version; and 55.75% and 54 out of 100 for the GameCube version.