One of the first games I got for my 3DS. For being a close to launch title, this wasn't too bad. Let's get this out of the way, it was repetitive. Very repetitive. The story is bland and definitely not a draw. What's the major draw of this game? Getting to play as nearly ever pokemon as you power your way through masses of others. Sure, it gets old and there can be a lot of cheap battles but it is fun. Pure clean fun.
It doesn't hold up well, even now. I would say with the library the 3DS has now, this is easily skippable. If you like pokemon though, you will have some fun with it. Just don't expect too much going into it and you will get more than what you expect.