Sonic Adventure was the big reason why I wanted a Sega Dreamcast back in the day. Just to see Sonic in 3D and be able to play through those stages in such environment was mind blowing. Granted, Nintendo did it first with Mario, but just to blast through the stages at fast speeds (with the exception of a few characters you get to play as) was an absolute joy. If this ever makes it to GOG, please let it be the International release of the game and not Japanese original that Sega seems to love to port over with the DX release time and again.