In the early 2000's, Sega's Sonic Team was floundering to find a way to help their flagship game franchise survive a rapidly changing gaming landscape that didn't seem to include Sega at all.  The Saturn had failed.  The Dreamcast had flopped, and it was looking like the writing was on the wall for everyone's favorite blue blur.  That was until Sonic Adventure 2 released and introduced a new character:  Sonic's rival, Shadow the Hedgehog.