Ah, but I've read the books, which I really enjoyed and have actually reviewed before (http://extemporanea.livejournal.com/131066.html). Given that the film was based on the first third of the first book, it's actually surprisingly faithful in plot (mostly) and very much in atmosphere. The slight off-the-wallness and mad pop culture touches (Buffy, computer games) are peculiar to the film, the book is more deadpan and understated, but the world-view is well-represented and the truly weird special effects pick up the vertiginous feel of the book very nicely.