Third time's the charm.
As most pokemon fans know, the first two generations of pokemon had two matching games, followed by an enhanced remake of them, with extra features. Pokemon Emerald is no different. in fact, it runs with the extra features and expands them greatly. Anyone who has played The Ruby or Sapphire versions of this game would know the story: Two rouge teams, named Magma and Aqua, where one is good and the other evil, and switching between these roles in the games, tries to awaken the game's mascot Pokemon, and the other tries to stop it. however, there is a plot twist in emerald, where both teams take on the role of villain, and try to awaken their respective legendary pokemon and control them to do your bidding. you stop them, but not without some intervention from the guardian of Kyogre and Groudon, Rayquaza. Apart from this, the majority of the storyline follows a similar course as that taken in Ruby and Sapphire.
However, the main difference between the two versions is noticed at the end of the game, where a new area is unlocked that allows access to new tournaments and events to compete in, replacing the situation of boredom that occurred after beating the game in Ruby and Sapphire. the game also brings in Pokemon from the Previously inaccessible second generation category, that were exclusive to The land of Jhoto in Gold Silver and Crystal, and could not be transferred over, due to hardware differences. the game also provides the only opportunity in the handheld game series to obtain two starter pokemon throughout the course of you adventure, with the second one being one of the rare Jhoto starters.
However, aside these and many more changes to the appearance of the game, the core gameplay that made the series so successful in the first place, has remained unchanged, and still remains tactical and fun as ever, making this one of the best games to hit GBA.