Sonic The Hedgehog

Enable the "Level select" and "Debug mode" codes. Enter the Special Stage. Transform into an object and go outside the Special Stage maze. Fall into the place with all the discarded objects and look for a red Chaos Emerald. If you find the correct one (there are multiple ones, but only one is collectable), the music will pause for a moment, then the emerald chime will play and you will spin out of the Special Stage as usual. When the results screen appears, you will see that you have six red Chaos Emeralds and it will say "Sonic Got Them All".

Enable the "Debug mode" code. Go to the end of Star Light Zone Act 1 without passing the sign. Press B and go under the floor at the end to find a secret underground hideout.

Hit him before he gets out his wrecking ball. While he swings the ball, jump (but do not hold it down) and hit him. Keep doing this until he is defeated.

Enable the "Debug mode" code. At the beginning of the level, create 50 rings and have Sonic collect them. Then, take Sonic to the end of the stage where you the giant ring. In the special stage, turn Sonic into an item and bring him to the end of the stage where the emerald is located. Turn him back and he will immediately get the Emerald. Repeat this until you have all six.

Enable the "Debug mode" code. While in Special Zone, transform into something then go as far left and down as possible until Sonic stops shaking. Turn back into Sonic. You will fall to a place which is spinning. Look around to find every different Emerald. Note: If you fall off this place, you will fall back to your original location. To prevent this, transform and repeat the process. This works in every Special Zone.

On Green Hill Zone Act 3, just after Sonic steps on the cap to explode the rocket ship, animals pop out. One is a rabbit, and the other is a blue bird who appears to be Flicky, who is from another classic SEGA game, Flicky.

If you are running out of time, go to a checkpoint. Once you get the checkpoint, press Start and select "Quit". Then at the main menu, select "Restart". You will resume at the checkpoint with the time reset, allowing you to continue. Note: "Restart" is a new option that will appear when you select the "Quit" option during a level.

To pass Scrap Brain 3 in a very short amount of time, press the button at the beginning of the level, and jump over the bridge to go in the path below the bridge. Jump over all the pits. By the last pit, fall down, and go up the path on the right until you see the red jumper. The jumper brings you to the next level.

You can almost always have the Special Zone entrance open (the giant ring next to the sign at the end of level Acts 1 and 2) by not losing your rings. If you do lose your rings, when you pass a checkpoint, intentionally die, then continue through the level without losing any rings. This works about 80% of the time.

Enable the "Debug mode" code. If necessary, use the level selection menu to go to the level. Run to the first wall you find, which should have a bomb enemy. Press B button and go through the wall so that you are between two green walls. Either press B again or just fly down to find three ring boxes and an invincibility box. Note: If you use the invincibility and press B, all the sparkles will stay where they last appeared. If you press B again, you will continue the time from last time you pressed B. This lets you use invincibility whenever desired. Note: The time with invincibility will eventually run out.