Sonic must buddy up with his former enemy, Knuckles the Echidna in order to defeat the evil Dr. Eggman. Play as Knuckles and tackle Robotnik and Metal Sonic with bare-fisted attacks, high-speed glides and wall-climbing power. Transform Floating Island into a huge 34 Meg Sonic-epic loaded with new secrets! “Locking-on” requires the additional purchase of SONIC 2 and SONIC 3, but its well worth the price of admission.