Gameplay
Instead of continuing to use the side-scrolling perspective introduced to the series by Zelda II: The Adventure of Link, A Link to the Past reverts to an overhead perspective similar to that of the original. While A Link to the Past still uses mechanics and concepts from the original game, it also introduces new elements and innovations. For instance, arrows are now separate items, as bombs are in the original, instead of using a Rupee to fire an arrow. A Link to the Past also takes concepts from The Adventure of Link, such as the magic meter, which is used by items such as the Lamp. Control of Link is more flexible than in previous games, as he can walk diagonally and can run with the aid of the Pegasus Shoes, an obtainable item. Link's sword attack was improved to swing sideways instead of merely stabbing forward; this gives his sword a broader range and makes combat easier. Link swings his sword as the default attack in future Zelda games, although stabbing is also possible in the later 3D incarnations.
Recurring items and techniques were introduced for the first time in A Link to the Past, such as the Hookshot, the Master Sword, the Spin Attack technique, the Ocarina, and the Pegasus Boots. Heart Containers that increase the player's maximum health (hit points) in the earlier two games are present, but many are split into "Pieces of Heart", four of which make up one Heart Container. Most of them are well hidden, adding replay value to the game. All dungeons are multi-level, requiring Link to walk between floors and sometimes fall through holes to land on lower levels.
A Link to the Past is the first appearance of what would subsequently become a major Zelda trademark: the existence of two parallel worlds between which the player travels. The first, called the Light World, is the ordinary Hyrule where Link grew up with his uncle. The second is what was once the Sacred Realm, but became the Dark World when Ganon acquired the Triforce. The Dark World is a corrupted version of Hyrule; the water is a dark, unpleasant green color, the grass is dead, skulls replace rocks and pots, and trees have faces. People change forms in the Dark World based on their nature; without an item to prevent it (in this case, the Moon Pearl), Link turns into a pink rabbit. Each location in the Light World corresponds to a similar location in the Dark World, usually with a similar physical structure but an opposite nature (e.g. a desert in the Light World corresponds to a swamp in the Dark World, a peaceful village in the Light World corresponds to a dilapidated town of thieves in the Dark World).
Link can travel from the Dark World to the Light World at almost any outside location by using a magic mirror, and can travel back to the Dark World again from the same location using a temporary portal left behind on the map at the point where he reappears in the Light World. Otherwise, Link must use hidden warp locations throughout the Light World to travel from the Light World to the Dark World. Travel between worlds allows for puzzles in A Link to the Past that exploit structural differences between the Light and Dark Worlds, as Link may travel to otherwise inaccessible areas in one world by warping from parallel but accessible locations in the other world.
Read more about this topic: The Legend Of Zelda: A Link To The Past