In Frontiers, Amy, Knuckles, and Tails have all been trapped, and Sonic must rescue them. During his frequent encounters with these characters, players see flashbacks to previous Sonic games. During ...

Sonic's greatest foe has not always been a playable character, but there have been some games where it was possible to play as Dr. Eggman. Regarded as far too anti-social and prone to brawling to have ...