Chibz said:
True, but these are frequently needless changes. Sprite changes, for example, that have no violence or sexuality oriented reasoning behind them.
Mario Brothers 2, was originally a completely different game yes, but a game that would likely sell far better to a Japanese audience than an American audience. Mario is a well known and loved series at that point, to allow this game to reach the greater audience, they would have switched out the sprites for something more recognizable to the north American audience.\
If Nintendo has shown us anything recently, it is they will do a lot for cash, and for penetration of their franchises. I would not at all be surprised if they consciously decided to switch the sprite sheets out so that they could rake in a bit more money.