This is the version of
Sonic Adventure for the
Sega Dreamcast that was released in the
USA and
Europe.
Sega was pushing
Sonic Team to complete
Sonic Adventure in time for the busy
holiday shopping season in Japan, and thus the game went to market with some glitches, errors, and problems with the camera. Given extra time to make the game all that it could be, the domestic version (and later Japanese re-release), dubbed
Sonic Adventure International, was everything that the original should have been and more.
So what was added? First was a complete English voice track as well as subtitles in English, French, Spanish, and German. The complete original Japanese voice track and subtitles are retained, making a total of voices in two different languages and text in five. Add to that the Internet feature that connects to the Sonic Adventure in-game website using the Sega Dreamcast modem, where you could enter World Rankings, download special features, trade Chao, or just chat. While most of the website graphics are loaded straight from the GD-ROM, all of the content is (supposedly) pulled from a remote server that is, sadly, no longer available. However, all is not lost - the website only served as a means to unlock extra content hidden on the disc. It is possible with some hacking and cracking to unlock these features on your own without using the website.
So what kind of web goodies were available? Most were just fun addons that changed the scenery of a level to something based on a holiday or promotion, or added a fun mini-game. Some addons added new options, such as changing the generic announcer voice to that of Sonic, Tails, or Knuckles.
So, game-wise, you're not missing out on anything by not having played the International version. However, this edition of the game is a little more polished and refined. This edition was built on and upgraded even more to become Sonic Adventure DX, the Nintendo GameCube version of the game, in 2003.