Pokémon Emerald beta

Unlike other Pokémon games, third version games rarely contain beta information because they are based on an already existing game. Pokémon Emerald is no exception.

Very little was changed in Emerald, in relation to Ruby and Sapphire Versions, with the exception of the Battle Frontier and storyline tweaks to better include the legendaries of Kyogre, Groudon, and Rayquaza. While there is no evidence to suggest the storyline was changed seriously, there is evidence that the Battle Frontier was changed slightly in various stages of development. However, these changes are minor and strictly relate almost entirely to building placements and static objects, such as fences.

Kanto and Sevii Islands

It is suggested by extras, such as music and map headers, that the Kanto and Sevii Island Region were originally supposed to be accessible somehow, and have full maps, in Emerald. For those who hack, on a mapping program, it is clear that the headers for each place in the Kanto region are there, though empty with no maps. Most likely, space limitations on the cart disallowed the programmers from adding the regions, or the areas in Hoenn where you can catch Pokémon from those regions were used as a substitute, because of time limitations.

New Music

Another proof suggesting an addition of the Kanto and Sevii Regions in Emerald, is music from FireRed and LeafGreen. Ruby and Sapphire, the base versions of Emerald, had Johto music in their coding, but Emerald clearly has new Kanto and Sevii music. Kanto and Sevii were most likely scrapped because of limitations, time-wise or somehow else.

"Special Area"

A new, empty header included with the other empty Kanto and Sevii ones is named "Special Area." There is no actual info on what would have been included in this area, but speculation can show it must have been a new route or section of one of the regions, maybe even allowing the capture of legendaries not in Ruby and Sapphire, with new events.