Pokémon Emerald was released for the Game Boy Advance on September 16, 2004 in Japan, May 1, 2005 in North America, June 2, 2005 in Australia, and October 21, 2005 in Europe. It is the companion game for Pokémon Ruby and Sapphire (as Pokémon Crystal was for Pokémon Gold and Silver) in the third generation of Pokémon games. It adds many new features to the gameplay, plot, and graphics.
The game was developed by Game Freak and published by Nintendo. Pokémon Emerald was generally well-received, with critics praising Emerald for having longer and more challenging gameplay, improved graphics, and new features. Some critics disliked the fact that the game seemed to be more of a "director's cut" than an all-new game. Despite this, the game ended up selling 6.32 million copies, the second-best selling game of 2005, and the third-best selling Game Boy Advance game of all time (outsold by Pokémon Ruby/Sapphire and Pokémon Fire Red/Leaf Green). It was spiritually succeeded by Pokemon Platinum.
Some changes from the previous games are very simple, from the small clothing changes of characters, to different battle intro animations. More drastic changes included changes to the plot to include both Team Magma and Team Aqua (and thus, both Kyogre and Groudon). Rayquaza is also incorporated into the plot. Gameplay changes were also made, with sprite animations to Pokémon added.
The gameplay in Pokémon Emerald is mostly the same as Ruby/Sapphire. Some minor changes included less clarity in whether or not a trainer battle is a double battle and the ability to re-fight with Gym Leaders. One of the largest changes was the Battle Frontier, which is a larger version of the Battle Tower in Ruby/Sapphire. The Battle Frontier is located on an island off of Hoenn (the region the three games take place in). Every building on the island is run by a Frontier Brain who fights with a certain style, and must be defeated.
Other than that, the gameplay is nearly identical to its predecessors. The game is played like any other traditional Pokémon game. There are three modes in the game: the overworld, battle screen, and menu. The overworld is a top-down viewpoint, where the player can control either May or Brendan, interacting with people and objects. Also in the overworld, the player can trigger battles (either with wild Pokémon or other Pokémon trainers). These battles differ. Wild Pokémon can be captured (although their hit points must be low enough to be capture) by throwing a Poké Ball (or its varying types). Trainer battles don't have this option to capture their Pokémon, as the goal is to merely make their Pokémon faint. In battle, the player has the option to either fight, use an item, switch out Pokémon, or run away (which can't be done in trainer battles). Fighting gathers all of the Pokémon in a trainer's party to gain experience points, and even points triggers a level up. Enough level ups, and the Pokémon may evolve into a new species of Pokémon.
Aside from the story changes, the game differs from Ruby/Sapphire in several minor but not inconsequential ways;
- Brendan and May have different outfits with an emerald theme.
- Pokemon sprites are now animated.
- The berry glitch that was present in Pokemon Ruby/Sapphire has now been fixed.
- The types and availability of Pokemon has been tweaked in both the wild as have several key encounters (eg. Marill is now available in Route 204, and the Elite 4 members have different teams).
- Steven is no longer the Hoenn Champion, and Wallace is no longer the Sootopolis City Gym leader. Wallace is the new champion, there is a new 8th leader named Juan, and Steven is a wanderer, available to fight in a new room in Meteor falls with his champion team from Ruby/Sapphire 20 levels higher, giving a nod to the trainer battle against Red in Gold/Silver/Crystal.
- Some Pokemon's abilities now have effects outside of battle if the pokemon possessing it is placed first in the party (e.g. Lightningrod attracts call more frequently)
- Natures can now be passed on through a specific method through breeding.
- Eggs can be hatched faster with Magma Armour/Flame Body ability pokemon being next to the egg.
- There are more gameplay features like Match Call from Pokemon GSC. Double battles are more common and can involve two trainers at once if seen by both at the same time.
- Some of the inevitable Legendary Pokemon are somewhat altered in level and moveset.
- Both Kyogre and Groudon are obtainable in the game at Level 70.
- both fossils can now be obtained; the first in the Mirage Tower, the second after completing the main story in a new area named the Underground Pass, which is home to the only area where Ditto is found in Hoenn.
- The method to unlock the tombs of the Legendary Regi trio has been changed.
- There is a new section in the Safari Zone that is accessible after the main story containing many previously inaccessible pokemon from the Johto region.
- The player is now limited in trading of pokemon during the main story. They can only trade pokemon within the Hoenn Dex during the story, and can only trade with Ruby, Sapphire and Emerald. They are granted the National Dex on completion of the story.
- Also, it is impossible to trade certain illegal legendary Pokemon (eg. Deoxys, Lugia, Ho-oh, Mew are untradeable if illegal, but Celebi still is), a feature carried over to Colosseum and XD. (NB: if a Pokemon is legitimate, there is no restriction in its trading)
- Some of the berries have influence over the effort value points (or EVs) obtained through battle, and can reduce their number, in exchange for making the Pokemon happier.
- The player can now hold up to 999 of a particular type of Item in one slot.
- Deoxys has a New form, called speed forme, to add to its Attack and Defense Forms from FireRed/LeafGreen. It is only usable in Emerald.
The Legendary Pokemon available without special events are:
- Rayquaza, a Dragon/Flying type at level 70. Found at Sky Pillar Roof.
- Groudon, a Ground type at level 70. Now found in Marine Cave.
- Kyogre, a water type at level 70. Now found in Terra Cave.
- Latios/ Latias, either of these Dragon/Psychic types at level 40 and are found roaming throughout Hoenn.
- Regice, Ice type at level 40.
- Regirock, Rock type at level 40.
- Registeel, Steel type at level 40.
The Legendary Pokemon available through Special Events on the cartridge are:
- Mew - Faraway Island - Level 30 (Old Sea Chart needed)
- Lugia - Navel Rock - (Rainbow Ticket Needed) - Level 70
- Ho-oh - Navel Rock (Rainbow Ticket needed) - Level 70
- Deoxys -Level 30 (Speed forme)
- Latios/ Latias - It is possible to capture the other Lati that the player didn't choose to find in the wild - (Eon Ticket needed) - Level 50