It brings a lot. lots of streetpass characters/teams/units, some dlc.
it has a somewhat dating simulator that allows you to marry people. Has partnering up to make a unit strong(though this is op as heck on modes other than hard/lunatic)
story is awesome, 3D and has nice visuals. there's tons of stuff to do in this game.
most maps suck though :[
well they dont suck, but it has bad terrain, and feels very lack luster compared to how other maps were in other fire emblem games.