If you want to play as character who doesn't go on Emerald Coast, do the following steps:

Tails:

1. Go to the Hotel in Station Square.

2. Go to the bottom right corner, where you will see an invisible wall. This may not work on the PC version.

3. You will see the outside and background of Station Square. Go left and you will be in Emerald Coast.

Knuckles and Amy's ways will be much harder.

Knuckles and Amy:

1. Get the man standing in front of the hamburger shop.

2. Bring him to the hotel.

3. Bring him to the right of the gate that is blocking Emerald Coast.

4. Try to get over him. This will take a lot of tries. For Knuckles, you should glide on him, and with Amy you need to Hammer Jump over him.

Note: If you go to act 2, you will not complete the stage. You will jump on a far-away spring and if you even try completing the level, don't.