It's just OK.
Gameplay/ Plot
This game is soooo much like the others it's not even funny. Find pokemon in the grass, catch em', train em, kick other people's butts. The plot is very unclear. There's this guy called Cyrus, leader of ( another ) group of baddies ( remind you of Rocket, Aqua, or Magma???). He says that the world is full of strife, that humans are destroying the world or something or other. He wants Dialga/Palkia so he can completely destroy the Earth, and recreate it with him the ruler. Why? We have no idea. He's another one of those crazy " I'm gonna destroy the world to make it better" people.
Graphics
This game has the best graphics out of all the Pokemon games. Not the best graphics on the DS, but still good graphics. The trees and some rocks are a little blurry when you move, but they are good.
Differences from old games:
PRACTICALLY NONE!!!! The only things different are the regions, people, and Pokemon. Really.
Overall:
Good game, but just soooooo nostalgic. Really. If the Pokemon company wants to keep their fans, they are gonna have to do something different than becoming champion ( Red, Blue, Yellow, Silver, Gold, Crystal, Ruby, Sapphire, Emerald, Diamond, Pearl, Platinum), figure out why you became human ( Mystery dungeon: Red Rescue Team, Blue Team, Explorers of Time, Explorers of Darkness) and saving the world ( Ranger, Ranger : Shadow of Almia).