Zelda II: The Adventure of Link

Zelda II: The Adventure of Link is the direct sequel to The Legend of Zelda, both originally released on the Famicom Disk System in Japan and then the NES in the US and PAL territories. Whilst retaining many of the features of its predecessor, The Adventure of Link altered certain elements of gameplay, most notably affecting movement and combat. Travelling across a large world map (not unlike those seen in the Final Fantasy series of videogames) would lead to enemy encounters which took place on a sidescrolling field of play rather than the top down perspective for which the series became known (and indeed used across Nintendo games from Zelda through to Pokemon and even Animal Crossing). This alteration to the series perspective caused some dispute amongst fans and has not been emulated since in any other 2D Zelda title.

Information provided by ZeldaWiki.org.