 The Japanese version of the game featured extra visual effects not seen in  the Western version. These were added in the period between the two release  dates. Changes made were rippling effects in the Labyrinth Zone waters,  moving clouds in Green Hill Zone, and the stages being listed in the correct  order in the level select menu. Some glitches and bugs were fixed too. This  is seen by some as the partial reason why the game was delayed in Japan until  after the Western release 