I guess the best way to describe this would be "intelligently insane". From start to finish, this is pretty much maxed out in weirdness, very much like writer Charlie Kaufman's later film, Eternal Sunshine of the Spotless Mind, only weirder. On the other hand, though, it's very psychologically deep and has some of the best performances of 1990s cinema (I was surprised when I learned that one of the main characters really was Cameron Diaz, and not just someone that really looked like her. ), along with beautiful imagery. It's very much a poetic film.
On the other hand, and although this is on purpose, all the focus being on originality and apparent randomness makes the film lack a certain level of cohesion. It's kind of like taking some sort of drug and seeing lots of crazy and mind-warping stuff, but then waking up in a stranger's backyard pool and wondering how and why you got there.
In a sentence:
Mind-bending, entirely unique, amazingly acted, precisely directed, and is basically the filmmaking equivalent of a poem: soak it in, analyze it, define its meaning, and move along.