Sonic Adventure was the best-selling Dreamcast game, selling over 2.5 million copies. It was the first Sonic the Hedgehog game on a sixth generation console, and was the first to feature free-roaming 3D gameplay (previous games in the series were side-scrolling 2D platformers). The game involved action levels with high-speed gameplay, and adventure levels where the character could explore the surroundings to advance the plot. It also featured a full soundtrack, with theme songs for each character performed by the band Crush 40. Well reviewed at the time of release, the 3D style would become the norm for all future Sonic games.

As with all Dreamcast game releases, it was produced on a GD-ROM disc, the only home system to use this format, which doubled the capacity of a normal CD-ROM by packing the pits on the disc more closely together. At the time of the Dreamcast's release (1998), implementing DVD-ROM technology was considered too costly. This may have resulted in the Dreamcast's downfall, compared to the DVD capabilities of Sony's Playstation 2, released merely a year later.