In multiplayer mode, highlight a character that has already been chosen by another player. Hold L and press A or X to choose that character for yourself and have two of the same character on the same track.
Unlock the Radiant Emerald and Super Sonic plus two of the metal characters, and then select a mystery character and then you will see in the list of all racers the Sonic and Super Sonic. This may not work everytime you do this however.
When playing Sonic The Fighters, follow these steps: 1) Get rival's health until one hit is left. 2) Get him colse to the ropes. 3) Preform an uppercut move. 4) If you K.O. Your rival, they might fly out of the ring!
Unlock Vectorman: Either play games in the collection for 5 hours or start the game with a saved file on your memory card from the Sonic Mega Collection to unlock Vectorman instantly. Unlock Vectorman 2: Either play games in the collection for 7 hours or play Vectorman more than once. Unlock Super Sonic (Sonic R): Complete The Game with all Chaos Emeralds collected and all the characters unlocked. Unlock hidden characters by collecting all 5 Sonic Coins on each stage and finishing in the top three.
Unlock Dr. Eggman (Sonic R): Win all courses.
Unlock Egg Robo (Sonic R): Get the five Tokens in Regal Ruins, finish in at least 3rd place and beat Egg Robo.
Unlock Metal Knuckles (Sonic R): Get all five Tokens in Reactive Factory, finish in at least 3rd place and beat Metal Knuckles.
Unlock Metal Sonic (Sonic R): Complete the game with all five Tokens in Resort Island, finish in the top three and beat Metal Sonic.
Unlock Tails Doll (Sonic R): Make sure you get all five tokens in Radical City, finish in the top 3 and defeat Tails Doll.
Unlock Super Sonic (Sonic R): Get the seven Chaos Emeralds.