>>33214828>YellowFollowing Pokemon's Pre-Alpha. Added literally nothing to the game. The ability to obtain all three Starters, which isn't revolutionary at all unless you were a friendless faggot, someone without two Gameboys, a Link Cable and two copies of Pokemon, or Stadium.
>CrystalThe Battle Tower and mildly changed Game Corner Trade-Ins.
>EmeraldThe Battle Frontier, catching both Groudon and Kyogre, a minor expansion to the Safari Zone, and choosing which Lati you want to roam Hoenn.
>PlatinumThe Battle Frontier, catching both Dialga and Palkia, the game isn't as hideously slow, and the Legendary Birds roaming Sinnoh.
And no, the Battle Frontier isn't significant at all.
It was an RNG-ridden fuckfest and I guarantee you only played the Battle Factory because it provided you with Battle-Ready Pokemon since you had no idea what teambuilding, EVs, IVs, Natures, Egg Moves or any of the conveniences you're used to now are.
The Battle Subway, Maison and Tree are ALSO RNG fuckfests that blatantly teambuild against you, making RNG even worse, and the idea is that you're now supposed to play online instead of battle facilities, hence the absence of the Battle Frontier and its playtime-expanding gimmicks.