It is very hard to give a film like this a rating as it is so weird and intense. I will try to do my best for a subjective review.
Good solid acting through and Peter Weller plays an excellent part despite the madness of the script (not a bad thing) and seems to keep a grip on whets going on even if the viewer is totally lost. The rest of the cast do very well including the talking cockroaches and type writers)
This is where it is a hard movie to review, if you like these types of films then it would be considered 5 stars if you like a more traditional film with an easy to understand plot you will not.
I think part of the plot is about not understanding what is going on as Peter Weller descends into madness and enters a bizarre sense of reality. I would also have to point out that it differs totally from the book.
My own personal opinion is that this is an excellent and very well made film. I say it's a solid 4 stars.