The Legend of Zelda: Link's Awakening might seem like the pint-sized sibling of the sublime Link to the Past, but many regard it as the superior release, despite the cruder visuals and sound. The 1993 Game Boy release was one of the first titles for the handheld which showed it could match its home console relatives when it comes to hosting deep and engrossing experiences, and it was remastered in 1998 on the Game Boy Color as Link's Awakening DX. It has since sold over 5 million copies worldwide.
However, in an interview with director Takashi Tezuka - originally printed in Game Informer issue 269 - it is revealed that the project began life without the express permission of Nintendo itself:
The main programmer wanted to challenge himself to create a Zelda experience on a portable system to see what he could do, and I was into the idea. We just had a passion to try and do something interesting. We didn't really have permission to do it necessarily. We were just playing around Once we got it to a certain level of creation and completion that we wanted to show, then we took it to the company and got permission to continue developing it, but initially it was just a little pet project of ours. Because we started it that way – just making a game we wanted to make – it may defy Zelda conventions. It might have interesting characters and situations we may not have had otherwise.
While we can't imagine that Nintendo would have blocked the game at any point, it's interesting to learn that Tezuka - now in a very senior role within the company - took the gamble based purely on his passion for the concept.