Welcome to the FX codes
Blue codes are old, they can be found everywhere or in a few places.
Red codes I've found in mags and sites but I can't get them to work. (they are probably fake)
Green codes- I don't have this game so I can't test it.
Orange codes are discovered by me, you might find them elsewhere but they were here first.
Sonic 3D Blast
Level Select - At title screen press B, A, Right, A, C, Up, Down, A
Level Select 2 - Beat the game and it will be there when you start it again
Play Sonic 3D Flickies Island - Put the game in a European or Japanese Genesis and the title screen will say "Flickies Island"
(note: If your wondering I used to have this game before the code came out)