Ghost World is not a unique movie. It does not try to accomplish much, it is not a grand scope, and while it has some decent actors and performances it shouldn't really be anything that special, but I really, really enjoyed it. In my mind it is Juno but done right, and I know it was made about 6 years before Juno so the comparison is not really relevant I just feel like it works so much better. There are a few similar elements but they are two different movies, though both star teenagers making difficult teenage decisions.
Life isn't easy for these first world people who live off plenty of food and have happy homes, they have relationship problems with their friends and family and no one seems to really know what romance is about. Enid and Rebecca are two fairly run of the mill outsiders who are basically hipsters before the word existed, loving to live at the edge, thriving on being non-conformist. They play pranks and do things which they think are random enough to attract attention. These are all negative qualities, and theoretically the viewer should hate them for these qualities, but they are oddly endearing. Enid is so confused by life and scared that we really identify with her, and the feelings of rejection and again fear held by Rebecca echo throughout life.
These characters are defined by the script, as the cinematography of the film is nothing special, just fairly typical style of the 2000's, many extended shots on seemingly unimportant details, examinations of rooms, and in general more focus on dialogue than anything else. One unique feature of the film is that it leaves almost nothing resolved at the end. It is not that it doesn't have an ending, it's just that the character's stories are not resolved, and life goes on for a bunch of clueless people. Enid gets on a bus that shouldn't exist at the end of the film and goes off to an unknown place, still unsure of herself but sure that she doesn't want to live the way she did.
The film chronicles the story of Enid and Rebecca's summer approximately, though no definite time-frame is really established. Enid plays a prank on a man named Seymour played by Steve Buscemi. The prank is really one of the cruelest moments of the film as she falsely returns a personal ad from the paper setting him up on a non-existent date. He comes into the shop and they watch him. Slowly it dawns on the pair that what they have done is cruel and Enid develops a fascination with him, going to where he lives and trying to find out what kind of person places that kind of ad.
In the end it is a character study on both of the protagonists, and their relationships with others. Around the second act Rebecca especially loses her screen time and is replaced by Seymour, directly showing the audience how out of touch Enid is becoming with the rest of reality. In the film a romance is hinted at between Seymour and Enid that becomes official about midway through the third act but it is more of fumbling in the dark than anything else. Neither knows exactly what to do about it given the large age difference and culture difference, and Enid especially doesn't know what to do as she has agreed not to go to college and her father is considering getting remarried changing everything she thought she knew.
With every end there is a new beginning and that is what the film ends with, the promise of more, of something that happens later that the audience does not know about and can't for it to be a fitting conclusion. Life does not simply stop in the middle, but the film does, because there is simply too much for a single film to cover, life is complicated and long and confusing, and the film shows that with a non-ending that still seems like a conclusion. One of the only sure things is that Enid will no longer be involved with the other characters, as for where they go or what they do the audience is unsure, but can make up their own stories.
In the end all movies about romance are just stories that will end one day, because very few truly last forever. That is why it is important to know when to end, when to stop the story and let everyone live happily ever after. If things go on too long they always end in death, Ghost Story is about people, and how they all seem to exist in their own little places, their own worlds, but no man is an island, and every decision affects others, often inadvertently. Life is all interconnected, and so are all the people in it.