Shadow's debut splits Sonic Adventure 2 into a hero story and a dark story, a pairing Sonic Team first released on the Dreamcast. The 2001 scripts put Sonic, Tails, and Knuckles on one side and Shadow, Doctor Eggman, and Rouge on the other.
The hero path climbs toward the Space Colony ARK while the dark path explains why Shadow was woken at all. Rail grinding, treasure hunting, and mech shooting sit in the same campaign instead of one shared moveset.
A later cube edition called Battle added more multiplayer on top of those two stories. This record is the adventure that introduced Shadow, with the extra battle modes arriving as a follow-up.