Everything about this film subverts the audience's expectations (whether this is always intended or not is debatable). The acting is very (and I mean very) amateur, but in a surrealist campy way. Take Napoleon Dynamite and turn it up about 200 notches. That's this film.
The film's secondary characters are all, well, characters. It's really something you have to experience. Their collective actions and dialogue is somehow both surreal and realistic at the same time. I've literally never experienced anything like this film.
What makes it even more entertaining is the contrast between the main character in this film (who is quite normal) and the world that orbits around her.
The script is super creative and, like the characters it contains, continually subverts expectations.
There's quite a bit to be taken from this movie message-wise as well. And what those messages are really depends on the viewer. It's probably a bit of a Rorschach test in this respect. For example, I found the main themes to center around nihilism and a desire to try and derive meaning from this worldview. But I can see others finding different messages within.
I really recommend this film. If nothing else, it is a singular viewing experience.