If you play on PS2 or PS3 or XBox you use START! And that answers you question!
This is the same for any version of Sonic the Hedgehog 2. The sound test is in the options menu.
There will be 2 options: Play as the original Sonic in the original levels, or play as the newer Sonic in levels like in Sonic Colors or Sonic Unleashed.
To be Super Sonic in Sonic the Hedgehog 2 you need all seven chaos emeralds and fifty rings. Once you have those jump up as high as you can and you will become Super Sonic!
yes it is, didn't u see the button that says 2 play
You don't; not every game has button codes.
No It does feature Sonic 2 and 3, but there is no way to make it multiplayer, and they removed the multiplayer (as well as options) from the games.
go to options and change the controls so all the keys are the up button...this might do it depending on what your computer runs on
Yes. Just go 2 options, and select the character you want to play as: Sonic, Tails, or Sonic and Tails. NOTE: If you are just as Tails, you cannot go SUPER SONIC, however there is a cheat to go SUPER TAILS, but you need both Sonic and Tails to do this.
press the escape button.
yes you just look on the game in the help or options
Press whatever you have set as the special attack button.
mix files with sonic and shadow