Downloadable content

Downloadable Content refers to any feature that isn't normally in the game, and so must be downloaded or obtained by other means.

Sonic Adventure
More info on this page. 

The majority of Sonic Adventure's DLC was celebrations of holidays, such as Halloween, Christmas, and Y2K. North America and Japan had different Christmas DLC's. NA's was a tribute to Christmas NiGHTS, while Japan's had Christmas trees scattered throughout Station Square, which played Christmas music when touched. There was also DLC celebrating the release of Samba De Amigo.

The rest of the DLC in this game was contests. North America had a Time Attack contest hosted by AT&T and Official Dreamcast Magazine. Europe had a Reebok DMX Competition. Japan had two contests; a hedgehog hide-and-seek and a Yukawa Senmu QUO Minigame.

Japan also had DLC of Jewel chao.