This is for Knuckles in Sonic 3 and works on Sonic Classic Collection. Start a new game and play through the entire game. After you have beaten the game, you are able to to pick any level on that save file. Now start on Zone 1 (Angle Island), go to the first swinging rope anf hang on it and then press Left, Left, Left, Right, Right, Right, Up, up, and Up. If done correctly, you will here a ring sound. Now die over and over until you get a game over, if you have any continues, do not use them, wait for the counter to goes to zero. Now go back to the same save file and this time select act 7 (Mushroom Hill). Go to the first pulley the is right past the dude that throws mushrooms and the Speed shoes box. (Knuckles needs to back track on Sonic's path once you get to the point where they merge) While hanging on it, press Left, Left, Left, Right, Right, Right, Up, Up, and Up. If done correctly, you will here a ring sound. Now die, and hold Y until the level reloads. Press B to confirm that the entire code has been enabled successfully. Get another game over if you wish to change levels. Just make sure to hold down Y when ever a level is loading.