Sonic 3D Blast
Go to the Press Start screen and enter the code: B,A, Right, A, C, Up, Down, A (or baracuda). You should then be taken to the main screen. Press the Start Option ad the level select will appear next. Choose your level and begin play.
Contributed By: ATadeo.
Quick Emerald Gain
Enter the Level Select code twice, and go to a level/act with Knuckles or Tails in it. Enter one of their bonus levels by collecting 50 rings. When the bonus level begins, press A + Start and you will recieve the emerald for the bonus level.
Contributed By: Lord GCN.
Do the level select code and start the game in any level. To skip levels, pause the game and press A.
Contributed By: Saturn Urameshi.
Stage Select (Alternative)
Beat the entire game with all the Chaos Emerald. After the credits, the stage select will be on.
Contributed By: sonic479.