You can't.
Chat with our AI personalities
You can play them in the Sonic Mega Collection Games, but not in Sonic Gems:i can go super sonic says:but you need to unlock sonic 3 and knuckles that's what i had to do!
knuckles in sonic 2 :play sonic 2 and sonic spinball 30 times
Brace yourself. You have to enter Sonic 3 (You don't have to play it, just enter and exit it afterwards.) Do this 30 times, and do this with Sonic & Knuckles 30 times.
You can't. It's not on Sonic Mega Collection or Sonic Mega Collection Plus. Sonic CD is only available on Sonic Gems Collection for Nintendo Gamecube.
i think so