"Legend of Zelda: A Link Between Worlds" was altered during development in order to play better on the Nintendo 2DS. This little nugget was divulged earlier today during an interview with series producer Eiji Aonuma.
In the interview with Gamespot, Aonuma the publication that he and his team didn't hear about the 2DS handheld until they were about halfway through the development of the game. Because of this news, the development team changed up some of the look and feel of some puzzles. Aounuma wanted to make sure that everyone understood that the game would have played fine without the changes. It just wouldn't have looked as good.
That means that the game isn't fundamentally different, it just got a few tweaks. The developer also talked about the frame rate and other little additions that the 3DS version of the game will offer. Aonuma says that the framerate for this particular title in the long running series will be rendered at 60fps. That is about double what Legend of Zelda games are normally rendered.
Aonuma said that if "Legend of Zelda: A Link Between Worlds" was rendered with a fps lower than 60, gamers simply wouldn't be able to see and enjoy the game the right way. The game is due to be released by the end of this year.