I first played this game at my cousins house.  I had played sonic 3 before, so I was eager to play sonic 2.  Man, they don't make video gmes like this anymore.  Simple, yet challenging, yet extremely fun.  I got the code for level select and super sonic shortly after I beat the game.  Go to options at the title menu, go to sound test, and put in 19,65,9,17.  You'll hear a sound. Then, press c.  The title menu will come on again.  Hold down A and press Start.  The level select will come up on the screen.  Go to the sound test at the bottom of the screen, and put in 4,1,2,6. You'll hear a sound, now you can be super sonic! Go to any level you want, get 50 rings and jump.