Have you played any of the other Pokemon Mystery Dungeon games? If so, you are in for a dissapointment story-wise. It's essentially the same story as every other Mystery Dungeon game but I assume you haven't so you should be fine. The story is fine standing alone but it's been reused so much that it's kind of annoying. The pacing is also extremely awkward. My only real advice for you is to bring lots of Reviver Seeds and Oran Berries with you.