...What exactly's so great about it?
Kanto had already been redone on gold and silver version. Not to mention they had it as a complete after-game add-on. Not the entire game. That time period has been gone for a long time. Repeating most of the NPC's original scripts and adding a few new maps and features and porting over most of the stuff from Ruby/Sapphire doesn't make it "revolutionary."
I might've been less hard on this game had it actually not had a load of useless extras that no player would ever use as their cop-out for not including the Johto land. The standards for Pokemon since Red and Blue have changed dramatically. Re-putting the player in the Kanto world with a bunch of extra bells and whisltes and a bunch of tiny "island" lands after the game that happen to fit half the Johto population is a total cop-out. I just can't understand the constant "OMFG THIS GAME IS REVOLUTIONARY!!!" reviews when all they did was make a few measly add-ons and use mostly material from previous games. Ruby and Sapphire at least introduced a brand new genre. Theres nothing new or great about re-making the oldest of the pokemon games, yet alone missing out on all the features from the old games. I was expecting from the hype a complete remake of both kanto and johto but instead got a way-too-short ruby/sapphire port with a few measly, useless features to keep the fans from throwing tomatoes at them on stage.
Summary: Just a rehash of the old games. Even if you're a pokemon fan, do yourself a favour and stick to when pokemon games werent made so incredibly linear, short and measly. Stick to ruby or sapphire which is a new world in itself with new ideas. Not just part of this annoying "retro" fad.