An amazing story. The mystery dungeon games are a step in the right direction, but I need something to get my feels going and it needs to be big and theatrical. With big unexpected twists that suddenly seem obvious the second time you play the game.
And most of all, it needs actual fucking motivation. Take Skyward Sword. It by far had my favorite Zelda, and she was by far the most likable character from the beginning of the story. Then she gets kidnapped from that point on I'm not playing the game to play the game. I actually want to fucking save her. This makes the immersion into the games SOOO much better. And Zelda locking freezing herself in the crystal is one of the few moments in gaming that has moved me close to tears. ( I seem to remember a moment like that in Okami, but can't place it now.)
I also think they should make it start like any pokemon game and have it seem happy and mundane like any other pokemon game, but the story starts to thicken a little ways into the game, and final concludes with a big dramatic final battle.