It's just like all the other Pokemon games really, but with another 100 or
so to catch. You still need a friend with the other game to get all of them, or
the internet so you can trade online.
The story is quite good, in that when you get to the crux of the story, it
doesn't just end and have you play the game by only catching pokemon. The story
continues on further, with other events. Not to mention that there are seasons
and other time related events, so in a way the game kind of forces you to play
it every few months, if you want to complete it totally.