This novel could be analysed in two different ways.
First, this is a Sci-fi novel, it greatly covers genre's most common topics, such as androids, lasers, mars collonization, flying cars and the like, talking about them without inventing/describing-widgets too much (a common error in this type of works).
Second, this is a Philosophical/Exsistencial novel, the role of nearly extinguished animals and electric animal is crucial. This text analyzes the human capacity of being empathic and to be faithful, which can't not be artificially simulated. Androids, as artificial beings, are in nature selfish and non-empathic, making this the only actual way they are distinguished from human beings, using a test which measures response speed to high-empathic questions.
The both styles combined make this novel on of the bests I've read so far, specially in the field of cyberpunk-type novels.
On the other hand, it's hardly related to the movie Blade Runner (which its screenplay is based on), I treat them as completely different stories.