Unlock the following Free mode characters by performing the corresponding tasks:

CHARACTER - HOW TO UNLOCK
Amy Rose - Complete all soleanna mystery missions with an "S" rank.
Blaze the Cat - Complete all soleanna mystery missions.
E-123 Omega - Complete all GUN commander missions with an "S" rank.
Knuckles the Echidna - Complete all town stage missions with an "S" rank.
Miles "Tails" Prower - Complete all town stage missions.
Rouge the Bat - Complete all GUN commander missions.