You have to unlock every Sonic & Knuckles lock-on individually by fulfilling specific requirements:
Blue Sphere: Play Sonic the Hedgehog and Sonic 3D Blast 20 times each.
Knuckles in Sonic 2: Play Sonic 2 and Sonic Spinball 20 times each.
Sonic 3 & Knuckles: Play Sonic 3 and Sonic & Knuckles 20 times each.
Note that you can simply enter and exit the game really quickly twenty times in order to fulfill these requirements.
Sonic Mega Collection Plus is the same as Sonic Mega Collection except with additional unlockables.
It is not on Sonic Mega Collection but it is on Sonic Gems Collection.
You can't use Lock-on technology like you could with Sonic Jam, however the lock-on technology created games can be unlocked by starting several games for set number of times. Which games and how many times - this depends on your platform.
Sonic Mega Collection happened in 2002.
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.
Sonic Mega Collection was created on 2002-11-10.
There is no such thing as Sonic Adventure Battle 1, nonetheless no Sonic Adventure is playable on Sonic Mega Collection.
You go to gamefaqs.com and look up the faq for sonic mega collection plus
Yes
i think so
You can`t.
you don't.