The early reviews for Ready Player One are in and they're overwhelmingly positive for the big screen adaptation of Ernest Cline's 2011 novel. There has been a lot of criticism and backlash over the movie's promotional campaign, with the most recent controversy surrounding a set of posters that pay homage to the classic pop culture movies from the 1980s and 1990s. Critics and fans of the book have been worried that Steven Spielberg created nothing but a nostalgia time warp, promoting the movies of Warner Bros. The standing ovation at the end of the late-night screening at SXSW may prove those preemptive thoughts wrong.

Forbes' Charlie Fink says, "Spielberg's Ready Player One is an instant sci-fi masterpiece," and many of the reviews follow the same path. Some even admitted to crying in the theater while watching the movie and look forward to sharing their experiences with their family and friends. For those wondering if the Steven Spielberg's adaptation of Ernest Cline's book is faithful, you may be out of luck, even though Cline co-wrote the screenplay. John DeFore with the Hollywood Reporter had this to say.

"A rollicking adventure through worlds both bleak and fantastic, Steven Spielberg's Ready Player One makes big changes to the specifics and structure of Ernest Cline's best-selling novel but keeps the spirit and level-up thrills intact."

Though some fans may be disappointed to know that Ready Player One is different from the source material, many will reportedly be happy with the job that Steven Spielberg did to "fix" the mistakes of the book. This will obviously depend on your view of the book, but many have accused Ernest Cline's book of simply being nostalgia-bait. Even though the marketing campaign leads you to believe that the movie follows that same pattern of the book, early reactions claim that Spielberg has crafted a story that doesn't rely on the nostalgia and engages the audience more effectively than the book.

Many of the critics that were in attendance for the Ready Player One screening are heaping praise on Steven Spielberg and calling it the "geekiest movie ever made." Erik Davis says that the movie is "classic Steven Spielberg," and Emily Yoshida tells fans to "relax, Ready Player One will indeed be the biggest thing in the world." While the majority of the reviews have been positive, there have been some that follow the backlash of the promotional campaign as well. Kristy Puchco calls the movie, "A cacophonous eye-sore."

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As is the case with nearly all movies, there's going to be different reactions, especially for a movie based off of a best-selling novel. However, the majority of the reviews out there are praising Steven Spielberg's work on Ready Player One and even has some people who had already decided that they hated it, change their minds. The glow of a special, secret screening at SXSW may have put an artificial glow on the movie as well, but we'll be able to find out soon enough when Ready Player One hits theaters at the end of the month. You can check out some of the reviews below, thanks to Erik Davis' Twitter account.