Sonic The Hedgehog 2

Level select:

Use the sound test selection on the options menu. Choose sounds 19, 65, 9, and 17 (in that order) and press C after each selection. A chime will confirm correct code entry. Press Start. Hold A and press Start when Sonic and Tails appear at the title screen.

Level skip:

This trick requires the "Level select" and "Debug mode" codes. Go to any stage and change into an object. Press A until you get to the object before the single ring. It is a strange looking object with a little Robotnik head (a machine where all the creatures appear from if you defeated a Boss). Place about ten in a row. Step on the first one until you see the score counting as if you completed the level. When you see that, step on the other buttons. You will go to the level after the level you were supposed to go to. For example: if you were in the Emerald Hill Act 1 you will now be in Chemical Plant Act 1. You can do this trick in any stage, but not in Dead Zone.

Enable the "Debug mode" code and choose any level except the Death Egg. Press C to cycle through the sprites until you see a glitched-looking prison egg. Return to Sonic again and get him to step on it. The "Sonic got through Act 1/2" message should appear. This will take you to the next level, and even works on Bosses.

In-game reset:

Enable the "Level select" code. Then, pause game play and press A. You should see the "Sonic and Miles 'Tails' Prower in..." message before you go to the main menu.

Toggle Tails or Miles:

Press Up(3), Down(3), Up at the title screen. A sound will confirm correct code entry. Alternately, press Up(2), Down(2), Up(4).

Extra continues:

Enable the "Level select" code. Use the sound test selection on the options screen. Choose sounds 1, 1, 2, and 4 (In that order) and press C after each selection. Highlight the "Player Select" option and press Start.

Super Sonic and Tails:

Enable the "Level select" code. Use the sound test selection on the options screen. Choose sounds 4, 1, 2 and 6 (in that order) and press C after each selection. Music will confirm correct code entry. Select any starting level and collect 50 rings. Sonic or Tails will turn yellow and can run at super speed, jump twice as far, and become invincible to enemies and spikes. The total number of rings will decrease during super mode. Your character will revert to normal when the ring total reaches zero. Note: Super Sonic or Tails can still drown, be crushed, and fall into bottomless pits.