Sonic Adventure

Sonic Adventure is a 3D-platformer released for the Sega Dreamcast on December 23, 1998JP. This is Sonic's first true transition into 3D as a platformer. It was one of SEGA's sixteen launch titles for the console, and SEGA wanted to provide the player with the same thrill of speed Sonic was founded on. Like other 3D platformers of the time Sonic Adventure's main story mode, and levels, are connected by hub worlds called Adventure Fields, a free roam environment to test the characters' abilities. It offered the unique advantage of having six playable characters Sonic, Tails, Knuckles, Amy, Big the Cat, and E-102 Gamma, all with their own stories and gameplay styles. After SEGA discontinued the Dreamcast on  March 31, 2001, Sonic Adventure was ported to the Nintendo Gamecube and other platforms digitally as Sonic Adventure DX: Director's Cut with enhanced graphics.

Plot
Instead of the game taking place on Mobius, it's on what seems to be Earth where Sonic and friends live among humans. After the events of Sonic 3 & Knuckles, a vengeful Doctor now dubbed "Eggman" is out to conquer the world. He learns about an ancient being called Chaos, a powerful creature that helped protect the Chao that inhabited the waters of the Master Emerald's shrine some thousand years ago.

Tikal, a decedent of the echidna tribe, would often visit the chao and was aware of the all-powerful Master Emerald, knowing it balances the power of the seven Chaos Emeralds. Her father Pachacamac, was leader of the echidna tribe and sought to steal the power of the Emeralds. An assault on the chao was lauched, Chaos retaliated by using the Emeralds' power to transform into a monstrous beast, Perfect Chaos, and wipe them out. Tikal then imprisoned chaos inside the Master Emerald along with herself to prevent world destruction.

Sonic and Tails' Story
At the beginning of Sonic Adventure, Eggman releases Chaos from the Master Emerald shattering it into pieces causing Angel Island to fall into the ocean again. He brings Chaos to Station Square test the creature against the elements and law enforcement. When Sonic sees the local police fail to defeat it, he jumps in and begins the Chaos 0 boss battle. Once is Chaos defeated, he retreats down a drain in the city call courtyard.

The next day Sonic is seen lounging on a poolside lawn chair, outside of the Station Square hotel. He notices Tails' tornado heading for a crash landing on Emerald Coast. As they catch up, Tails informs Sonic to meet him at his workhop in the Mystic Ruins. While playing either Sonic or Tails' story, you will encounter Eggman waiting there to fight against The Egg Hornet. Regardless of winning the battle, Robotnik cheaply steals the Chaos Emerald from Tails. He feeds it to Chaos, transforming him from Chaos 0 into Chaos 1, becoming taller with one giant arm. Sonic and Tails know at this point its time to stop Robotnik again.

They race through new zones from point A to point B, capturing a chaos emerald at the end. By the end of Casinopolis Sonic and Tails are in possession of another Chaos Emerald, but they get a surprise attack of knock out gas from Eggman. He steals the emerald feeding it to Chaos, creating Chaos 2. Sonic and Tails don't give up, gaining another two emeralds by the end of Ice Cap.

They encounter Knuckles in the Mystic Ruins, who is also searching for Chaos emeralds. Like in Sonic 3, he was tricked by Eggman into thinking Sonic was trying to steak the Chaos Emeralds. A fight between the two breaks out, which causes Sonic to drop his Emeralds. Eggman waiting for the opportunity, grabbed the emeralds feeding them to Chaos creating Chaos 4. where Chaos takes on an even larger form. He introduces his new air fleet The Egg Carrier, and flees with Chaos.

Sonic and Tails part ways with Knuckles, and rush to Tails' workshop to chase down the Egg Carrier. Sky Chase Act 1 begins, as the two attempt to lower the Egg Carrier's defenses. Eggman retaliates by releasing a hidden weapon, a highly powerful laser beam from the nose of the ship at the Tornado. Sonic and Tails get separated along the way, with Sonic landing in Emerald Coast and Tails landing in the Mystic Ruins. An unconscious Tails has flashback to the moment he first saw Sonic, around the area he landed in the Mystic Ruins. Tails awakes and explores the area until he comes across a cave entrace to the Sand Hill mini game.

Sonic sets out to look for Tails in Station Square, but runs into Amy Rose who is protecting a "birdie". Amy asks Sonic to be his bodyguard. Sonic having more urgent matters at hand refuses and tries to lose Amy. She catches up with him at the entrance of Twinkle Park, noticing a sign that says cute couples get in free. Sonic and Amy see ZERO approaching, and E-series robot built by Eggman to retrieve the Flicky. Bullheaded, Amy runs right into the Twinkle Park anyway, and Sonic follows to keep her out of danger. After leaving Twinkle Park, Sonic can't find Amy anywhere until he notices her being carried away by ZERO inside the glass tube of the trestle bridge leading into Mystic Ruins.

Now in the Mystic Ruins, Tails repairs his Tornado which he has now been fitted with a Chaos Emerald for extra power and flys after Eggman. Sonic continues his chase on foot toward the Egg Carrier, making his way through Red Mountain until he see's Tails flying overhead. Tails picks Sonic up, starting the Sky Chase Act 2 mini game. This time Tails has a secret weapon, a battle transformation called the Tornado 2. They defeat the ship's outer defenses and main laser that struck them last time. They board the Egg Carrier, and both race through the level Sky Deck. Sonic defeats E-102 Gamma and Chaos 6, and leaves the ship once Tails notices its beginning to lose altitude.

Sonic goes through Lost World, Hot Shelter and Final Egg, to a final boss fight with The Egg Viper.

Knuckles Story
Simultaneously, Knuckles, the only remaining echidna, sets out to find the shards of the Master Emerald and repair it.

Amy and Gamma's Story
In Station Square, Sonic's friend Amy finds a Flicky being pursued for a Chaos Emerald in its possession, and decides to protect it. When both are captured, Amy convinces Gamma not to work for Robotnik, who helps her to escape, before seeking out and destroying the other robots in his series, sacrificing himself in the process.

Super Sonic (last story)
Despite Sonic managing to disrupt Robotnik's plans, Chaos manages to absorb all the Chaos Emeralds. Transforming into Perfect Chaos, it rebels against Robotnik and attacks Station Square, devastating the city. Having experienced flashbacks from Tikal, who was released herself, Sonic realizes that Chaos has been in constant torment and sorrow, and that imprisoning it again will not stop it. Using the Emeralds brought to him by the others to transform into his super form, Sonic fights Perfect Chaos and defeats it. Returned to normal, Chaos calms down when he sees the Chao living peacefully in Station Square. Realizing its pain is gone, Tikal decides to take it somewhere safe to live in peace. With Sonic having won, he decides to leave to pursue a fleeing Robotnik.

Activating a new series of robots, including one named Gamma, Robotnik orders them to find Froggy, an amphibian who had eaten a Chaos Emerald after mutating from contact with a piece of Chaos the night he was released.

Gameplay
The game is completely in 3D. The way that the game works is you start out in a hub world. The hub worlds connect to the games levels, boss fights, and the choa worlds. You can also go around the hub world and talk with the civilians. The way you get upgrades is by finding them in the hub world.

Sonic's stages are high speed platforming. Sonic's stages are about being fast. Tail's stages are about outrunning either Sonic or Doctor Eggman. Knuckles stages are about finding the Master Emerald. So that means that Knuckles stages are treasurer hunting. Amy's stages are slow platforming. Amy is one of the slower characters. Big the Cat's stages are all about fishing/finding Froggy. E-102 Gamma's stages are also  slow platfroming.

Sonic begins the game with the Homing Attack, his unlockable abilities are Light Speed Dash,

Action Stages
Action Stages are basically playable levels. This is the only type of area where Sonic or any of his companions will encounter enemies (most boss battles appear to take place in the Adventure Fields, but they are actually in Action Stages designed to look like the Fields). There are eleven Action Stages, accessible by different characters. However, unlike previous Sonic games, Action Stages are not made up of Zones and Acts. Instead, the game plays more like each Adventure Field is a Zone and the Action Stages are the Acts in the Zone. The Action Stages have separate areas that could be considered "Acts", but they are not separate levels, as in previous games.
 * Emerald Coast
 * Windy Valley
 * Casinopolis
 * Icecap
 * Twinkle Park
 * Speed Highway
 * Red Mountain
 * Sky Deck
 * Lost World
 * Final Egg
 * Hot Shelter

Sub Games
Sub Games are mini games based on action stages. When you complete a sub game on Story Mode, you unlock it on the sub game menu located on Trial Mode. For some Sub Games you can use any character, but some of them require the use of the character(s) from Story Mode. You can get two emblems from each sub game, from achieving high scores. The second emblem requires a much higher score than the first. The scores appear at the end of a sub game. You cannot get two emblems per character but can use any to get one emblem (if it allows more than one character).

Adventure Fields
Adventure Fields are non-linear game stages, generally designed for (light) puzzle solving, exploration, and plot advancement. They contain very few items (enemies, rings, etc.). Every Adventure Field links to the other two Fields and a Chao Garden. They also have four Emblems each. They are each packed with various power-ups for different characters.

There are three Adventure Fields:
 * Station Square: a large, metropolitan city, and is the location of Sonic's first fight with Chaos. Eggman plans to destroy it and construct "Robotnikland" on its ruins. A train here takes you to the Mystic Ruins.
 * Mystic Ruins: a large mountainous area and the largest Adventure Field in the game, containing the crashed Angel Island. A train here takes you to Station Square. Deep in the jungle, a Ziggurat can be found. Tails' workshop is in this area. It also has a base home to Eggman.
 * Egg Carrier: Eggman's massive flying airship. This is the Adventure Field where most characters fight their final bosses (except Sonic and Tails). The Egg Carrier has two layouts and multiple transport devices unique to this field.
 * Egg Carrier Crashsite: This area appears when the Egg Carrier crashes. This is an early stage for E-102 Gamma. There are two boats, one leads to Station Square while the other goes to the Mystic Ruins.

Sonic Adventure DX: Director's Cut
There are many differences between the two versions, in DX, there is a mission mode when you finish the whole story of a character, it consists of 60 missions which you complete by doing different tasks in the adventure and action stages. There is also the minigame collection when you collect a certain amount of emblems in the game.

Games

 * Sonic the Hedgehog
 * Sonic Drift
 * Sonic Chaos
 * Sonic Spinball
 * Sonic the Hedgehog 2
 * Dr. Robotnik's Mean Bean Machine
 * Sonic the Hedgehog Triple Trouble
 * Sonic Drift 2
 * Tails' Skypatrol
 * Sonic Blast
 * Tails Adventure

Bosses

 * Chaos 0
 * Egg Hornet
 * Chaos 4
 * Chaos 6
 * Egg Viper
 * Egg Walker
 * Chaos 2
 * Zero
 * E-101 Beta
 * E-103 Delta
 * E-104 Epsilon
 * E-105 Zeta
 * E-101 Mark II
 * Perfect Chaos

Unused Voices
Sonic Adventure/Unused Voices