Sonic Adventure DX: Director's Cut

Sonic Adventure DX: Director's Cut (ソニックアドベンチャー デラックス) is the enhanced port of the Dreamcast video game Sonic Adventure. It was released for the Nintendo GameCube on June 2003 and for the PC on 2003 in Japan and 2004 elsewhere. This version of Sonic Adventure contains several exclusive features.

Missions
Sonic Adventure DX features 60 missions spread across the six playable characters, where special tasks must be completed in the game's Adventure Fields and Action Stages.

Unlockable games
Sonic Adventure DX features many unlockable games previously available on the Game Gear. If the start button of the second controller is pressed, the game screen will split, and two games will play at the same time. Additionally, Gear-to-Gear cable emulation is present, enabling the games that have two-player modes to be played if both players access the proper options within the game. These games were to be included in the Dreamcast version, but were scrapped due to time constraints. The same goes for the reintroduced feature of being able to play as Metal Sonic. A new Game Gear game is unlocked for every 20 Emblems the player gets, up until 100, then every 10 after that, or by completing 20 more of the 60 missions.

The following is a list of the unlocakable games:
 * 1) Sonic the Hedgehog (8-bit)
 * 2) Sonic Drift
 * 3) Sonic Chaos
 * 4) Sonic Labyrinth
 * 5) Sonic Spinball
 * 6) Sonic the Hedgehog 2 (8-bit)
 * 7) Dr. Robotnik's Mean Bean Machine
 * 8) Sonic Triple Trouble
 * 9) Sonic Drift 2
 * 10) Tails' Skypatrol
 * 11) Sonic Blast
 * 12) Tails Adventure

Changes
Sonic Adventure DX: Director's Cut includes all of the basic alterations made to Sonic Adventure International as well as several additions/changes. They include:
 * Changed graphics: The main characters were redesigned with higher polygon counts and shading technology was also implemented for effects such as rippling water (shading effects were not present in the PC version, however).
 * The original 60 fps frame rate was restored. Unfortunately, due to the unstable nature of the Sonic Adventure engine, the game frequently skipped frames, usually in an uneven pattern (causing noticeable choppiness), even in places where few objects were displayed, and/or where the Dreamcast version did not slow down (however, some effects that caused slowdown before do not affect the frame rate in the GameCube version). Cutscenes ran at a lower frame rate, but this seemed to have been intended, for cinematic purposes.
 * Some sound effects, such as when collecting rings and emblems, were lower in pitch, while the losing rings sound effect was higher in pitch.
 * A Camera option was added to the pause menu, allowing the user to select either the original Auto Camera or the newly added Free Camera, which is usually closer to the character. In Auto Camera mode, the C-Stick can be used to get a first person view of the environment. In Free Camera mode, it rotates the camera around the player.
 * Changes (mostly minor) were made within the levels themselves in an effort to help solve some of the game's problems concerning collision detection. However, many glitches were not fixed, and some new ones were actually added. Some have to do with inconsistency in the port (for example, some windows still reflect the original Dreamcast graphics).
 * The Internet connection feature was removed. Very few of the downloadable content from the Dreamcast version, such as the Chao Garden's black market and additional voice packs, were included in the GameCube port. However, unlike the sequel, most of the online features were not incorporated into the GameCube game and remained exclusive.
 * Many changes to the Chao System were made, such as more interaction with the Chao, the ability to see their stats, as well as changes to the appearance of the Chao. The Chao Adventure VMU minigame was removed (instead replaced with a Game Boy Advance connection feature). The Chao System was overall very similar to the Sonic Adventure 2: Battle Chao System.
 * 60 Missions were added for an all-new Mission Mode, which tasks the player with completing certain goals within the Adventure Fields and Action Stages, similar to the Mission Mode found in Sonic Jam ' s three-dimensional Sonic World.
 * Metal Sonic becomes a playable character in Trial mode, as a reward for collecting all of the Emblems. He plays identically to Sonic, although his standing animation seems to be glitched. Oddly enough, he also cannot breathe underwater.
 * Cream the Rabbit makes several cameo appearances during the main game and Mission Mode. She can be seen flying around Station Square.
 * As mentioned above, a Mini Game Collection mode was added allowing access to 12 Sega Game Gear games. This is the first time Sonic Drift and Tails' Skypatrol were released in the US and Europe.
 * The ability to skip cutscenes by pushing Start was added.
 * A map, found on the pause menu while in Adventure Fields, was added. This is especially useful when navigating the Mystic Ruins jungle.
 * The train used to transport from Station Square to Mystic Ruins is now blue instead of red as in the Dreamcast version.
 * Some voice effects were changed like when Tails begins to fly or when Amy swings her hammer.
 * The characters' mouth movements match up with their lines in each respective language. However, this seems to cause more graphical glitches (such as Tails sliding along the ground in Super Sonic's story in English). In Dreamcast versions, the lip-syncing did not match either language.
 * Loading times are significantly shorter than in the Dreamcast version.
 * In the opening title sequence, Tails has his mouth open when he flies by the shattering windows. His mouth is closed in the Dreamcast version.
 * Oddly enough, the final picture after each character's ending credits still reflects their Dreamcast designs.
 * Knuckles' purple eyes are more prominent like in his official artwork.
 * Amy's boots are more rounded in the front, unlike the Dreamcast version where they were square-tipped.
 * The models of the characters in Sky Chase now have increased polygon count.
 * In both the PC and GameCube versions, Sonic and Amy's eyelids are the same color as their fur unlike the Dreamcast version where they are the same color as their skin.
 * In the original, their hands were one solid object with lines in them, while in the port, their fingers are separated from each other.
 * The PC version does not include a variant of the Tiny Chao Garden, and instead has a generic Chao transporter.
 * Japanese language settings are set as the default in the Japanese region, which was not the case in Sonic Adventure International.

Reception
Reviews were generally less positive than those of its Dreamcast predecessor, scoring more than 20% lower than the original release.

Trivia

 * In the Mission Mode of Sonic Adventure DX, the player occasionally has to collect gold Sonic medals. Interestingly, these are the same gold Sonic medals from Sonic R.
 * Oddly enough, in the Casinopolis stage, if the player were to go into the bathroom and step into one of the shower stalls, Sonic will start to wash his quills for a few seconds.
 * When Amy is "remembering the good times" in a Sonic the Hedgehog CD-inspired daydream, she is being rescued by Sonic while the two are chased by Metal Sonic. However, she is in her redesign instead of her old one. Interestingly, the backdrop resembles the original version of Windy Valley.
 * Cream the Rabbit makes cameo appearances in Sonic Adventure DX. She can be seen flying around Station Square when certain levels have been finished, or when a few special cutscenes have been played.
 * She also appears in the same manner in the HD port of Sonic Adventure even without having the DX DLC installed.
 * In Sonic Adventure DX, when Amy is captured by Zero, one can see that she has her Dreamcast version design rather than her new design.