The following contains spoilers for both the Ready Player One movie and the book it is based on.
The Ready Player One movie was never going to be a note for note remake, such a thing was ultimately impossible. Still, whenever a beloved book gets the film treatment there are moments fans want to see on the big screen, but sometimes those are the moments that get cut. Such was the case with Ready Player One.
In the case of this movie, there were actually very few elements that made the transition from book to screen. While every reference in the novel was likely a big deal for somebody, there are a few very special ones that we were really hoping we'd see on the screen, and were more than a bit disappointed that we did not.
Parzival's car is one of the highlights of Ready Player One. It's a classic Back to the Future Delorean complete with a flux capacitor and a red Knight Rider LED light on the front. However, the version in the movie is missing one element that is referenced in the book. It doesn't have the Ghostbusters logo on the doors. Adding it wouldn't have changed much, so we can guess this is one set of rights that the filmmakers just weren't able to secure. In an additional Ghostbusters reference, the original license plate on the Delorean actually read ECTO-88 in the novel, rather than being Parzival's name, as it is in the movie.
The Tomb Of Horrors
The logo for Dungeons and Dragons appears a couple of places in the Ready Player One movie, but the famous tabletop RPG factors much more in the book, as the infamous D&D module Tomb of Horrors, is recreated inside the OASIS and Parzival has to fight his way through it. The physical layout of the Tomb is specifically described in the module written for Advanced Dungeons and Dragons, but it has only ever existed in the minds of the people who have played through it. Seeing it come to life would have been awesome for those of us who grew up playing, and those who still play, D&D.
Ready Player One the movie puts its heroes inside one of the best-known films of all-time, but the book does this several times. While actually recreating a movie within a movie was always going to be difficult to pull off in an entertaining way, one place they could have pulled it off was with Blade Runner. In the novel, Parzival realizes the Jade Gate is located inside a recreation of the Tyrell Corporation, requiring him to use a Voight-Kampff machine. Seeing Parzival walk through a perfect recreation of Tyrell's office would have been awesome, as would the moment he realized that was the place he needed to go, thanks to an origami unicorn.
There are few faces that are so immediately associated with the 1980s as Max Headroom. Whether you remember him from his talk show, his Coke commercials, or the cyberpunk TV series of the same name, he was an icon for the decade. Max is nowhere to be found in the film, which is unfortunate because it would have been great to bring Matt Frewer in to voice the character once again. In the novel, Parzival/Wade uses a version of Max as a sort of A.I. voice control interface for his OASIS system. He's like Siri, but he's got basic intelligence and he interacts with Wade as well as following his commands. Max would have added some decade appropriate comedy to the overall movie that would have been funny without feeling out of place.
While it's absolutely true that seeing Japanese hero Ultraman appear in the Ready Player One movie would have gone over the heads of a large part of the western audience, for those of us who were familiar with the character, it would have been a thing of beauty to see. Seeing a Gundam go one-on-one with Mechagodzilla was great, but Ultraman has a particular old-school style to him that would have been perfect opposite the classic movie monster. He's also, admittedly, a bit corny, but that would have only added to the fun watching him teat Mechagodzilla apart.