My real complaint that keeps this from being "great" in my mind is that it's not doing anything particularly new (story-wise, mechanics-wise, etc). I don't think games have to always be doing something fresh--sometimes they can just take existing ideas and remix them into something polished, like here--but I also don't know that this is a game that sticks with me over time or that I feel compelled to recommend strongly to other people as something they should to play either.