Sonic Adventure Trilogy

Sonic Adventure Trilogy is a 3D action platformer game developed by Sonic Team and published by SEGA. The game contains versions of Sonic Adventure 1 and 2 that have been completely remade from the ground up, with enhanced visuals and enhanced gameplay, it also has a completely new game, Sonic Adventure 3, which serves as the conclusion to the Sonic Adventure saga.

Sonic Adventure
Sonic the Hedgehog

Miles "Tails" Prower

Knuckles the Echidna

Big the Cat

Amy Rose

E-102 Gamma

Super Sonic (in the last story, also unlockable in actual stages)

Metal Sonic (Unlockable non-canon story)

Hero Story
Sonic the Hedgehog (Speed)

Miles "Tails" Prower (Mech)

Knuckles the Echidna (Treasure)

Dark Story
Shadow the Hedgehog (Speed)

Dr. Eggman (Mech)

Rouge the Bat (Treasure)

Last Story
Sonic the Hedgehog and Shadow the Hedgehog (Speed)

Miles "Tails" Prower and Dr. Eggman (Mech)

Knuckles the Echidna and Rouge the Bat (Treasure)

Super Sonic and Super Shadow (in the last story, also unlockable in actual stages)

Hero Story
Sonic the Hedgehog (Speed)

Miles "Tails" Prower (Flight)

Knuckles the Echidna (Treasure)

Amy Rose (Exploration)

Espio the Chameleon (Combat)

Silver the Hedgehog (Puzzle)

T-Bot-92 (Mech)

Ignis the Dragon (Shoot)

Dark Story
Shadow the Hedgehog (Speed)

Lex the Raven (Flight)

Rouge the Bat (Treasure)

Iris the Cat (Exploration)

Metal Sonic (Combat)

Infinite (Puzzle)

Dr. Eggman (Mech)

E-123 Omega (Shoot)

Sonic Adventure

 * The level design in some levels has been slightly tweaked.
 * Some parts of the story have been rewritten to be more coherent.
 * Big's levels have been reworked, the fishing is still apart of his gameplay, but the controls have been improved and there's more actual action in the stages.
 * Metal Sonic is now his own character with his own moveset instead of being a clone of Sonic.
 * The hub world now has a mini-map, as well as a fast travel option that lets you play any level from the hub world instead of having to travel all the way to it's location just to play it (provided you've already completed it).
 * Boss fights where you fight against another playable character have been made more challenging, with each character now having their own unique attack patterns.

Sonic Adventure 2

 * Certain actions now have their own separate button as opposed to them all using the "interact" button (examples being the Light Speed Dash, which is now activated by pressing the right trigger like in Frontiers and the Volkan Cannon, which is now activated by pressing R2/RT/ZR).
 * The radar in Knuckles and Rouge's treasure hunting stage now detects all three emeralds as opposed to just one emerald at a time.
 * You can now switch rails more easily by pressing L1/LB/L and L2/RB/R like in the boost games.
 * You can now transfer Chao to and from SA1's Chao Garden.
 * The 2 player mode can now be played online.
 * The alternate costumes from the 2 player mode can now be used in single player.
 * The special characters from the 2 player mode (Amy, Metal Sonic, Tikal, Chaos, the Chao Walkers) can now be used in single player after collecting enough emblems.
 * The beeping from Tails and Eggman's missile lock-on has been made less annoying.
 * The kart controls have been vastly improved,
 * The level design of Aquatic Mine, Death Chamber, Mad Space, Crazy Gadget, Eternal Engine, and Cannon's Core has been improved.

Both Games

 * The homing attack now has a reticle.
 * Both games have a newly remixed soundtrack (the original soundtrack can still be toggled in the settings).
 * Chao minigames can now be played online.
 * Super Sonic and Super Shadow can now be used in regular stages after completing Super Sonic's story in SA1 and the Last Story in SA2.

Story (Sonic Adventure 3)
WIP