The game in Ready Player One is OASIS, a virtual world that has largely supplanted "real world" institutions such as schools, workplaces, and even families. I'm not sure Ready Player One is a very sophisticated book, certainly not anywhere near the level of creativity or intelligence that Stephenson displays in Reamde, but nevertheless it is hugely entertaining and a must read for anyone (like me) who came of age in the 1980s.
The plot of Ready Player One revolves around a contest for ownership of the OASIS company and its ubiquitous and all encompassing OASIS game, initiated by the death of its Bill Gates founder like James Halliday. The year is 2044, the oil has long since run out, and the U.S. has devolved into a poor and crime ridden nation of slums, environmental catastrophe, and evil mega corporations. The protagonist, Parzival - aka Wayne Watts, lives his life (like almost everyone else in 2044) inside the virtual world of the OASIS - plugged in with 3D immersion goggles and haptic full-body suits. In order to win Halliday's game, he must defeat evil corporate competitors in a series of virtual challenges and quests - all of them revolving around various 1980s movies (War Games) and classic arcade video games (Joust, PacMan, Tempest etc.) and other bits of Reagan era popular culture. If you lived through Family Ties and the Atari 2600, and never really escaped either experience, then it is probably wise to drop what you are doing and read Ready Player One.
Stephenson's Reamde, on the other hand, is both hugely entertaining and brilliantly crafted. How many 1056 page books do we read that feel too short? Cryptonomicon  is one of my all time favorite books - Reamde is better. At least 3 great books in one, from the immersive virtual world of T'Rain, to the Russian mafia, Chinese Hackers, and Islamic terrorists, Stephenson somehow makes it all hang together. The characters in Reamde may be a bit one-dimensional, but the dimensions on display (basically insane bravery and skill in the face of overwhelming odds) could scarcely be more compelling. Reading Reamde is the best immersive experience I can imagine, superior to any video game or Hollywood movie on offer.
What are you reading?