When a book is made into a movie, change is inevitable. After all, books have the freedom to be as long as they need and require at least some use of the imagination. Plus, books have the advantage of a narrator, giving you a constant inner-stream from at least one character.

Still, the hope with any adaptation is that fans of the book will leave the theater satisfied despite the differences and non-readers will come away loving the story just as much as they would have had they devoured the book.

For Steven Spielberg's Ready Player One, the book-to-movie transition was a "really difficult adaptation," Tye Sheridan, who stars as Wade Watts/Parzival, told MTV News at a recent press day for the movie in Los Angeles. "Steven's the first one to say that there are 10, 12, 15 movies inside of Ready Player One," he added, noting that the director worked closely with author Ernest Cline and screenwriter Zak Penn to condense the expansive world described in the book into a visual extravaganza that lasts under two-and-a-half hours.

As a fan of the book himself, Sheridan was satisfied with the transition. "It feels like the reason I love the book, all those reasons are embedded in the film," he said.

It's up to the audiences to decide if they agree, but in the meantime, here are five major differences and two comforting similarities that we spotted in the film, in theaters now.

Difference #1: The Set Up

There are some differences that are apparent just from watching the trailer — things like the movie taking place in Columbus, Ohio, rather than Oklahoma City. This feels like a minor change, considering the general atmosphere still has that over-populated, energy-depleted gloom. (For book fans, the new location also feels like a nice nod to Oasis founder James Halliday’s home state.) Even the Stacks are pretty similar to their description in the book, although Wade's trailer in the movie is smaller than described in the book, with him in a single-family unit and living only with his aunt and her boyfriend. This could feel like a new display of wealth, which also comes to play when Wade swaps in his human persona for his avatar. The movie grants Parzival a dope outfit and sick ride. No more "Great outfit, slick" jabs for Wade3!

Difference #2: School's Out

Actually, no more anything for Wade3. The Oasis Public School system doesn’t show up in the movie, so if you were mostly looking forward to field trips to King Tut’s tomb and the human heart, maybe try a documentary instead. Of course, no OPS means that in the movie, the keys and Halliday’s Easter Egg are hidden in unfamiliar places, blessing fans of the book with a spoiler-free journey through the Oasis — and that’s all I’m going to say about that!

Difference #3: Gunter Bible Update

Anorak’s Almanac gets a pretty cool upgrade thanks to some movie magic. In the book, the Gunter bible is a PDF file filled with words and sentences. In the movie, it’s an immersive multi-media library that anyone in the Oasis can visit and explore, giving moviegoers the visual experience they paid for.

Difference #4: Easter Eggs For All

The ample pop culture references sprinkled throughout the book also get the benefit of Hollywood's movie magic. Whereas all of the mentions are flat-out written into the book, a ton of '80s classics are dropped into the movie without much broadcast or fanfare, cleverly giving audiences Easter Eggs of our own.

Difference #5: Meeting Art3mis

One of the major critiques that came after the initial craze over the book settled was that Ready Player One personifies everything that's wrong with nerd culture and the red flags that resulted in Gamergate. Put very simply, in the book, Wade seeing love interest Art3mis as merely a trophy to be won was interpreted by some as a symptom of the toxic masculinity that tarnishes fandom. Well, I am happy to report that the movie aims to correct that misstep by giving its two female characters, Art3mis and Aech, more agency. Rather than waiting until the end to connect with his virtual friends, Wade’s clan enters his life earlier in the movie, allowing them each to play integral roles in the quest to save the Oasis and broadening the idea of what it means to be a hero.

Similarity #1: Easter Eggs For Book Lovers

Even though some events play out differently in the movie, there are certain things from the book that pop up in the movie in new places. Basically, these discrete modifications serve as additional Easter Eggs and clues for fans of the book. I’m not going to give any specific examples here because I promised not to spoil anything, but let’s talk after you see the movie.

Similarity #2: The General Worlds

In essence, the worlds that are described in the book are believably the same as the worlds portrayed in the movie. Even though many details go unstated, altered, or are left out entirely, none of that detracts from the epic experience of traveling between the dystopian reality of 2045 and the fantastical world of the Oasis.