Not a full review or anything but just my thoughts. I have put about 10 hours into the game.
I almost passed on this game but I got my hands on X and Y this past weekend and I am happy to report that the game feels much better than the previous installments that I have played. I had Heart Gold on DS and before that Ruby on the Advance. Ruby was awesome and I loved playing that game but I never felt like newer versions were a whole lot different.
Granted I have not played them all but just looking at the installments I have not played, friend and player reviews for them, you could tell that there was not a whole lot of changes. This is a game for me that is more fun to play every couple generations where enough time has gone by or significant improvements added for it to feel fresh again and for you to rediscover why you liked it in the first place.
That said I feel like this version has raised the bar a bit. The core mechanics are still intact for the series but everything just feels more refined overall. The addition of roller skates that you get early speed up your characters movement and it makes a big difference getting around.
In addition things added like the Exp. Share that you also get early, when equipped, allow the Pokémon in your party of 6 to get some experience from the battle even though they may not have fought that battle. This is huge because it was such a grind to level a young Pokémon later on in the game. Lastly, there is a new type called Fairy.
The graphics are gorgeous on the 3DS and look much improved with better-looking character models and sprites especially when your Pokémon are duking it out. The camera zooms and pans on the action as you take down your opponents.
Above all else the addictive "Catch 'Em All" gameplay makes this a must buy for any Pokémon fan with a 3DS in my opinion.