I'm mostly immune to hype these days, but heck....the game isn't even out and I already have character scenes in my head. I don't think that has happened ever before. And I've been playing these games since the 1980s.
As for disaappointment...well, many things can diappoint a little but it takes a lot to ruin a game for me if the story mostly works. Such as the disaster of Mass Effect 3's ending.
