I regard "The game-players of Titan" as one of Philip Dick's top... say 5 books. It is certainly hard to discriminate, especially with so many criteria on which to judge such an author's work, but this book contains everything, in good quantities and excellent quality.
Seasoned readers will feel immediately familiar with the story's opening with the hero 'going down' already. All the landmarks of the author's style are there: the suicidal hero, his equally problematic close circle, the vague overwhelming threat, the public figure who steps in, precogs, telekinetics, aliens, a novel social structure, various states of mind (drug-induced and otherwise) and the strange sense of satisfaction that comes at the end of the book when nothing seems to have been resolved proper.
It is quite a strange world in which Pete Garden lives: he wins and loses land titles on, and has his marital life directed by, a board game much like monopoly, but with the element of bluff added in. This game has been introduced or, rather, enforced by the Titanians although they apparently lost the war with the Earth. Moreover, they seem to be taking over again, but by much more subtle means this time. But does this make the game, which all Terran landowners are obliged to play, more or less important?
The plot twists, which mean you can never know for sure what has really happened or who is telling the truth, start very early in this novel and continue throughout. There is subtle humour/irony as well as outright hillarious scenes (Pete Garden fighting with his drug cabinet in order to get enough pills off it to commit suicide without it calling for help being a handy example), and one of the most ingenious solutions to a seemingly insurmountable problem, which is most notable about the book. The scenery is a rapidly degrading world, more suggested than described, which is usually what books win over films about.
Overall, and this is the part the non-Philip-Dick-fan will find less unfamiliar, it could be adequately described as a 'fast-paced thriller' (probably by some Hollywood nut) with various strange, sometimes unforeseen and a few bewildering elements interacting in a way as to have the reader constantly guessing, sometimes as often as about a new thing in each paragraph, in order to bring the plot to a conclusion of revelation in a rather anti-climactic way. If this last is contradictory, it's a credit to the literary and imaginative genius of the author that it is, also, precisely so.