Shadow the Hedgehog is a video game for the Gamecube, PS2, and XBox that centers around the story of Shadow trying to recover his memory, a goal he has been pursuing since he first appeared in Sonic Adventure 2. At the beginning of Sonic Adventure 2, his memory was incomplete, and after almost dying at the end of the game, he lost it completely. He continued to seek knowledge of his past in Sonic Heroes. In Shadow the Hedgehog a three-way war rages between the Black Arms, GUN, and Eggman, in which Shadow sometimes takes part while struggling to gather all 7 Chaos Emeralds, which he believes hold the key to his past. He finally regains his memory during his confrontation with Black Doom in the "Last Story" of the game. Shadow the Hedgehog was developed in the United States. This game features a mission based style of play similar to Team Chaotix's story in Sonic Heroes.
The story begins with Shadow standing on a hill outside the city of Westopolis at sunset. A newspaper blows by in the breeze and has the headline of celebrations taking place now that something called the Black Comet has come back in it's 50 year cycle. As it blows off into the distance, Shadow struggles to remember who he is due to his amnesia and constantly thinks back to the one memory he seems to have left.
The scene switches to Shadow's point of view, running down a long metallic hallway with a girl as if trying to escape from something. However, soldiers suddenly appear and shoot the girl before Shadow can react, prompting him to cry out the girl's name. Maria.
As Shadow ponders who this "Maria" is, a gaping hole opens up in the sky over the city. Strange black and red creatures descend from the clouds and begin to cause pandemonium in the city. Shadow turns to leave, not caring about the humans until someone calls out his name. A large floating figure, known as Black Doom, appears and tells Shadow to bring him the Chaos Emeralds "as promised" before disappearing in an explosion.
Fuelled with desire to seek out his past and find the truth behind Black Doom's words, Shadow speeds off into the city.
The story's progression then depends on the player's actions of deciding the path Shadow takes by choosing which missions to complete in each stage. Some scenarios will reveal certain information about Shadow's past including flashbacks to the ARK and Maria and the connection of the events onboard the colony to others, such as the GUN Commander. All of the story paths have their own unique endings depending on how much Shadow aids the protagonists or Black Doom and the Black Arms:
- If Shadow chooses to aid the Black Arms in their conquest of the planet, then he will either become a servant of the Black Arms, defeat and kill Eggman or even betray the Black Arms and claim the universe for his own. In the Darkest scenario, Shadow vows to destroy the planet with the power of the Chaos Emeralds.
- If Shadows chooses to remain neutral to both parties, then he will become convinced he is simply an android copy of the original Shadow and then kill Eggman.
- If Shadow chooses to aid the protagonists in combating the Black Arms, he will either become the protector of the ARK, become convinced that he is nothing more than an experiment gone horribly wrong and thinks he should never have been created or fight with Sonic to proclaim himself the most powerful hedgehog in the world. In the best Hero scenario, Shadow defeats Black Doom and vows to destroy the Black Arms and keep his promise to Maria.
However, all of the endings are actually distortions of the truth. The true story of Shadow's past is told in the Last Story, which can only be unlocked by obtaining all 10 endings.
In the Last Story, Shadow is confronted by Black Doom after gathering all of the Emeralds. Black Doom commands him to give up the Emeralds so that they can begin the Ritual Of Prosperity. Sonic and the others (including Eggman) then arrive and tell Shadow not to listen to the alien leader. After it is revealed that Black Doom wishes to harvest humans as an energy source, he uses Chaos Control to warp the Black Comet down to the surface of the planet.
Black Doom then explains that he helped Professor Gerald create Shadow but only in return for the Chaos Emeralds, which were needed to bring the comet down to the surface. This reveals that Shadow was actually created using Black Doom's DNA. As Eggman is in disbelief that his grandfather would betray the planet, Black Doom paralyzes everyone with a special gas and leaves them to be devoured by alien worms. As the end seems near, Shadow suddenly hears Maria asking for help and he breaks through the paralysis. Black Doom flees, leaving Shadow the only hope for the planet.
Shadow catches up with Black Doom and is suddenly wracked with pain. Black Doom tells him that he can control him as they have the same blood running through their veins. Shadow refuses to believe it as the scene switches to the ARK where Charmy, Vector and Espio race to hack data disks that they found earlier in the game. They finally get inside and a film showing a sane Professor Gerald begins to play. He refers to Shadow as his son and tells him that he is the only hope for the planet. It is revealed that the only way to defeat the Black Arms is to destroy the Black Comet using the Eclipse Cannon, a powerful weapon built into the ARK. As the video ends, Maria steps into the frame and gives Shadow the inspiration he needs to break through Black Doom's control. Black Doom escapes and prompts Shadow to use the Chaos Emeralds to become Super Shadow and fight the alien leader. Black Doom (now in his Devil Doom form) fights Shadow and is defeated.
Shadow then uses his superpowers to Chaos Control the Black Comet into the planet's orbit and tear it apart with a blast from the Eclipse Cannon. Everyone below cheers in joy as the alien threat is destroyed forever. In one final scene on board the ARK, Shadow looks at a picture of Maria and Gerald before tossing it away, remarking "Goodbye forever...Shadow the Hedgehog".
For some missions, Shadow teams up with various allies from the series, some new and old. Potential allies for Shadow include Amy Rose, Charmy, Espio, Knuckles, Maria, Rouge, Sonic, Tails, Vector, Doom's Eye, E-123 Omega, and Eggman. The allies act as combat support and guidance and give help to Shadow should he need it. When an ally is not present, Shadow himself talks to the player about what they need to do.
In the PS2 and Gamecube versions of the game, a second player can connect a 2nd controller and play a character as an unofficial "co-op mode". This can't be done with Eggman, Doom's Eye, or Charmy and will not work on the Xbox version.
During Shadow's journey, 3 different types of enemies are present in the missions. GUN, the Black Arms and the Eggman Empire will all try to attack him regardless of who he sides with in a mission. The GUN enemies, who are hunting him down due to their Commander's orders, include human troops and robotic troops as well as traditional GUN Beatles and walkers and defeating them earns Dark points. The Black Arms include gun and sword wielding humanoid aliens, flying creatures, and missile-launching worms and defeating them earns Hero points. The Eggman Empire enemies are Eggman's typical robots, including the Egg Pawns and bomb-throwing jugglers, as well as Shadow Androids. Defeating them earns either Dark or Hero points, depending on who the opposing side is.
Shadow's abilities in Shadow the Hedgehog are similar to those from Sonic Adventure 2. He can jump and jump dash/homing attack, as well as spin dash, light dash, and slide to attack while running, but he also has the ability to use weapons (including guns, swords, rocket launchers, etc.) and drive vehicles that he finds or commandeers. Shadow also keeps his ability to wall run from Sonic Heroes.
Shadow can use a variety of weapons found throughout each stage. Ranging from pistols and machine guns to close combat weapons, Gatling guns, bazookas, and even laser rifles. Weapons are commonly found in boxes and dropped from enemies. When a weapon is first picked up, Shadow receives some initial of ammunition for that weapon; more ammunition can be gathered by picking up more copies of the weapon. Only one weapon can be held at a time, and when Shadow runs out of ammunition for his weapon, he will toss it aside and it disappears. Even melee weapons such as swords have ammunition points, which may represent their durability.
Six special weapons can be unlocked in Story mode. The first five are each unlocked by completing either the Hero or Dark mission of one of the five Stages (and their ammo can be increased by completing both the Hero and Dark missions.) The last special weapon, the "Shadow Rifle" is unlocked upon completion of the Last Story.
These special weapons are contained within black boxes with Shadow's head on it. When one of these boxes is opened, it drops all unlocked special weapons.
Shadow had ability can use two different Chaos Powers, based on how the player makes him act towards enemies/allies. Destroying Black Arms, healing wounded or dead GUN troops and civilians and putting out fires gives Hero points and fills up Shadow's Hero gauge. Destroying GUN troops, environmental objects and healing Black Arms gives Dark points and fills up Shadow's Dark gauge.
When Shadow's Hero gauge is full, Shadow becomes invincible, gets unlimited ammunition, and can activate "Chaos Control" which fast forwards through the stage (or slows down time in boss battles) until the Hero gauge is empty. When Shadow's Dark gauge is full, Shadow gets the exact same benefits as with the Hero Gauge, but uses Chaos Blast, which uses creates a huge blast of chaos energy, destroying everything nearby. Chaos Blast can be used up to three times before the Dark gauge is drained.
There is also a third Chaos Power that only be used in the Last Story, called Chaos Spear.
Interestingly, while both sides are often seen exchanging shots with one-another, they will rarely ever hit each other. This is because the developers wanted all the enemy deaths to be a result of the player's actions. The player cannot simply wait out a fire fight until enemies are weakened, but must instead do the work themselves.
The story mode of Shadow the Hedgehog is broken into stages, with cut-scenes in-between. The first stage of a game of story mode is always Westopolis. After that, however, the next stage played is determined by which "mission" was completed in the previous stage. For example, if the "Dark" mission is completed in Westopolis, the next stage will be Digital Circuit, whereas if the "Hero" mission is completed, the next stage will be Lethal Highway and if the "Normal" mission is completed, the next stage will be Glyphic Canyon. Each stage (except for Last Story, which has only The Last Way), has 2 or 3 missions, which can be Dark, Normal, or Hero. There is a door in each stage, which requires 5 keys to unlock. There are bonuses such as weapons and shortcuts behind the door.
- Westopolis (Normal)
- Central City (Pure Dark)
- The Doom (Semi-Dark)
- Sky Troops (Normal)
- Mad Matrix (Semi-Hero)
- Death Ruins (Pure Hero)
- The ARK (Pure Dark)
- Air Fleet (Semi-Dark)
- Iron Jungle (Normal)
- Space Gadget (Semi-Hero)
- Lost Impact (Pure Hero)
- GUN Fortress (Pure Dark)
- Black Comet (Semi-Dark)
- Lava Shelter (Normal)
- Cosmic Fall (Semi-Hero)
- Final Haunt (Pure Hero)
Shadow the Hedgehog uses the traditional A through E ranking also featured in Sonic Adventure 2/Sonic Heroes, etc. A certain minimum total score is required to earn each ranking, with A being the most points and E the ranking earned when less than the required number of points for a D are earned. The number of points required for each ranking varies between stages and between missions within each stage. There are also three types of points earned during the level, and the way the total score is calculated depends on which mission is completed. Normal points are earned by collecting rings and items. Dark points are earned by destroying GUN troops (and sometimes Eggman's robots) and things in the environment (such as signs and lights.) Hero points are earned by destroying Black Arms (and sometimes Eggman's robots), healing wounded or dead GUN troops and civilians, and putting out fires. Your total score for Normal missions equals your Normal score plus your Time Bonus (Hero and Dark scores are ignored.) Your total score for Dark missions equals your Normal score plus your Dark score plus your Time Bonus minus your Hero score, and your total score for Hero missions equals your Normal score plus your Hero score plus your Time Bonus minus your Dark score. By earning an A rank for all stages, "Expert Mode" - a challenging version of all stages is unlocked, similar to "Super Hard Mode" in Sonic Heroes.
Final levels do not feature neutral missions, causing the player to choose either a Hero or Dark boss battle as their final fight.
- GUN Fortress-
Hero: Rouge the Bat. Find the Chaos Emerald.
Dark: Doom's Eye. Destroy GUN's computer.
- Black Comet
Hero: Knuckles the Echidna. Find the center of the comet.
Dark: Doom's Eye. Destroy GUN's troops.
- Lava Shelter
Hero: E-123 Omega. Find Dr. Eggman.
Dark: Doctor Eggman. Activate the base's lava defenses.
- Cosmic Falls
Hero: Vector the Crocodile. Find the Computer Room.
Dark: Doom's Eye. Find the Chaos Emerald
- Final Haunt
Hero: Sonic the Hedgehog. Find Black Doom.
Dark: Doom's Eye. Activate the Comet's defenses