Having read the book, I was greatly disappointed by the movie. The key appeal of the book, which I think the film makers misunderstood, is not simply the general concept of a virtual reality Internet and all the flexibility it offers. It was the idea of all the pleasures and nostalgiac pop-culture interests from a persons childhood co-existing in a common universe: Star Wars, Star Trek, Dungeons and Dragons, etc... all within reach of each other and interacting. To make that work, you needed the 1980s nostalgia element from the novel, which the movie almost completely threw away.

However, there were some things the movie did better than the book - the reason I didn't just give it a 1-star rating. First, the movie spends more time in the real world, outside the OASIS, and offered more of a resolution to plot threads going on there, for example the fate of the villain. Also, Tye Sheridan was charismatic in the lead, and created a more sympathetic hero in Wade than the book version. In the book, we don't see much indication that Wade develops any appreciation of the real world or the dangers of getting over-immersed in the OASIS. In the movie, however, Wade eventually does learn to see this, which I think was a big improvement to the character.

So to sum up, if you could combine the good from the book with that from the movie, you might have the perfect story. I won't ever understand why the film makers made such a drastic departure from the 80s nostalgia themes of the novel. I guess it was out of a concern that the original story targets too narrow a demographic. It's true that only GenXers will appreciate the majority of the references, some of which are pretty obscure. However, that didn't hurt the success of the book, so I don't see why it was an issue in its film adaptation.