2) Release in US Delayed
The US Version of the game was released 18 months after the Japan release. Nintendo was worried about the reception of the game so they did not release it in the US right away. They were pleasantly surprised, of course, when they got the sales figures for 1988 which showed two million copies sold. Ultimately, it has sold over 6.5 million copies; making it the 4th best-selling game of the Zelda franchise.