First off, it is a nice movie. But the deviation from the book is so massive that it's no longer Ready Player One but a different story set in the same universe where the main characters have the same names by pure coincidence.

While some changes were certainly necessary for a movie adaptation, the scope and type of changes in the movie are just insanely bad. Changing the main characters and story to such an extent is not only unnecessary but laughably stupid.

In a frame set by the book the challenge design makes no sense and the story progression outside the OASIS is completely counter to anything that fits the world built by Ernest Cline.

Overall, it can be very much recommended for people who have no interest in the book but as someone who has enjoyed the original this was just yet another in a long series of severely disappointing adaptations.