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.
Sega Dreamcast
Sonic Adventure 2 (demo)
Picture Disc - Turn on the Dreamcast with the lid open, go to the Music screen, put the Sonic Adventure 2 demo disc in and close