First at all: If you like watching movies I recommend you NOT to watch this one. Why? Afterwards you won't appreciate any other movie so easily anymore...
Actually I don't wanna give rise to any excessive expectations but it is almost frightening how perfect, intense and beautiful this work of Einar Gudmundsson is. When in most movies there is at least one aspect spoiling the whole thing, like good actors but horrible dialogs or a nice scenery but low budget cinematography in Angels of the Universe" there is nothing of this ambivalence. Really everything is just great, even (and not least) the soundtrack with the magnificent Sigur Rós.
In this story about Pall, a student that goes schizophrenic after being dumped by his girlfriend, especially the dialogs (and monologues) deserve some attention: together with (and sometimes in sharp contrast to) the plot they range from depressing and fatalistic to the whole opposite of comical and totally absurd. What is more, they are often (with quotes from Hegel and Shakespeare) of such a poetic beauty that the movie almost drifts into a surreal sphere and is only saved to the real world by its incredibly authentic actors.
One of the other comments was already referring to another point: This movie is no trivial entertainment for relaxing in the evening. Despite of several comical reliefs in between it is largely disturbing, partly cynical and bitter, and most of all sad. It is a modern poetry about a life of insanity with all its emptiness, rage and solitude.
Finally: When you've seen the movie watch it again. There are some great visual metaphors and allusions in it that you realize only when you look twice and connect them with the moral of the story". And of course: read the book, it contains a lot more of the small funny stories in between and also makes you understand some things in the movie a bit better.