Halliday and Ogden's avatars in the OASIS, Anorak and Og, are both revealed to be infinitely powerful compared to any other player avatar. And of course they would be, as both avatars are Wizards.
Halliday gave a secret hint to beating the Lich in Joust. What's the trick to beating the lich in Joust? Ask to play from the left side, i.e. Player One. Now, what does the game tell everybody every time they log in? "Ready Player One."
The movie adaptation chages some things around, for example making I-r0k The Heavy instead of a minor Unwitting Instigator of Doom, and replacing a lot of the anime references. The prologue of the book also mentions that there have been several movie and tv adaptions of the story, most of which got a lot of things wrong. The book is the real story; the movie is an in-universe retelling of the story.
A common criticism of the story is that certain social norms, which generally trend toward being more progressive over time, haven't advanced in the book's society despite it being set in the future—for example, Aech being disowned for being gay, when gay rights have already advanced noticeably even since the book's publication. But this can be justified by the wave of 80s nostalgia kicked off by the Egg Hunt robbing these issues of their visibility and in effect resetting society to 80s values. It also makes sense that our narrator Wade doesn't comment on this—because as a white male, he's still so privileged that he might not even notice.
If Halliday ultimately viewed OASIS and his various media passions as distractions, albeit pleasant ones, why did he create a contest that would require people to plunge headfirst into those distractions, devoting years of their lives to memorizing obscure trivia and avoiding the reality Halliday claims to see as important? Because he knew that even Og was starting to lose passion for it, meaning even the closest thing he had to a friend was unlikely to fight to prevent a merger with IOI, which would basically destroy the OASIS even if he was unable to imagine a nihilistic fanatic like Sorrento. So he kept that as a prize for the contest, plus a fat stack of cash to sweeten the deal, but left his final revelation as a bit of life advice.
Bonus points; many reviews compare Ready Player One to Charlie and the Chocolate Factory — just like Wonka, Halliday wanted an heir, and saw this as the best way to ensure that the next controller of OASIS would love it as much as he did. Sure, it's a distraction, but it's also his greatest creation.
Also, in the film adapation of this book, Aech's attempt to kiss the woman in Room 237 takes on new meaning for people who also read the book. As a woman RPing as a man, and someone who never saw The Shining, Aech's intent to follow the signals in the room is a pretty clear message that filmmakers kept her status as a lesbian in the movie. Well done, Sir Steven.
Wade sees the Hunt as like a Dungeons & Dragons campaign. And Halliday asks Morrow to keep an eye out on it in case something goes wrong. So, as his last request, Halliday is asking Morrow to DM for him like how they did when they first met in high school. How's that for Book-Ends on their relationship?
Given how much people even today love incessantly quoting Monty Python in general and Holy Grail in particular, it seems inevitable that reciting the entire movie would be part of the final challenge. With bonus points for getting the accents right, even.
The Sixers are all well-equipped, high-leveled and combat trained, yet in the final battle they're at the wrong end of a really loopsided Curb-Stomp Battle (in the book they even started with Mechagodzilla, the Voltron lions, and five mechs from Battletech and Evangelion, and lost all of them except Mechagodzilla so fast the lions couldn't even form Voltron). Thing is, they're all combat trained but not experienced due getting their levels and equipment thanks to IOI paying for it and blatantly cheating, while their opponents are all Gunters who got their levels and equipment the hard way... And gained actual experience using what they had.
Not many people catch this, but Wade's plan on accessing information inside IOI comes from War Games, as does his escape plan. Think about it: Wade uses a backdoor installed by a person who worked on the systems. Wade is able to burrow in deeper while inside, which gives him access to be able to get what he needs to get out of his small living area when the time calls for it (similar to how David uses what's inside the infirmary when he's in NORAD to escape, basically using what he has access to). And how does Wade escape? He pretends to be a regular member of the IOI staff, walking out the front door (David pretended to be a part of a tour group passing through NORAD and leaves through the front door as well).
At the end: The remaining High Five are all extremely wealthy, but the Crapsack World they live in is almost beyond saving (to the point that real life nuclear explosions are glossed over in a throwaway line), while the evil Mega Corporation still exists, holds much of its power, and knows their real life identities.
Even though Nolan Sorrento has been arrested, he was not the head of the organization and every horrible action he took (including ordering several murders) was approved by someone who outranked him.
Furthermore it's shown that IOI was perfectly willing to throw Sorrento under the bus when it suited them, such as when Wade demands his job in place of being another Sixer. They will probably say that he acted without their knowledge and leave him to whatever fate the courts decide.
Though given that Wade points out that he now has a quarter of a trillion dollars to work with, so he now has access to his own mega lawyers. Beyond that, he also massive support from most of the players (which make up most of the planet's population) and from the co-creator of OASIS himself. There's a reasonable chance they could take down the Mega-Corp for good.
Also the final battle results in most if not all of the population of the Oasis 'zeroing out'. As currency is tied to the avatar this means they were all left penniless and having to start their lives from scratch. Despite being left with God-like powers Wade's narrative never states if he uses them to reverses this. If not then the economy is likely to crash with the world in complete poverty!
If America is this screwed up, what does the rest of the world look like?
Wade starts out living in the slums, having to work just to survive, basically living most of his life in a small abandoned van. And he says he's one of the luckier ones.
Well, it depends, namely on the reliance of fossil fuels and oils, especially for transportation. Some places, such as in parts of Europe, would be better and other nations as well (like Japan). Others that relied more on it, like the USA and Russia are probably in worse conditions. Granted, this is excluding any other potential problems (since nuclear explosions were mentioned) that could make this difficult to guise.
In developing and overpopulated countries like India or even the Philippines, reliance on fossil fuel-based transportation was more a luxury than a necessity, with too many cars resulting in gridlocked traffic and pollution. One wonders if the energy crisis might have solved this issue somewhat.
And, ironically, the Post-Peak Oil problem is probably solving a lot of environmental ones; Global Warming can't get much worse since hardly anyone can afford gasoline anymore (Assuming they've also run low on coal and natural gas, which seems likely since neither one is depicted as being a reasonable solution to the transportation problem.). As a result of that, people are consolidating in large cities within walking distance of food distributors instead of expanding smaller communities as they can't go far from cities anymore, so new construction has ceased, ending the demand for wood from clear-cutting. Everything outside of the cities is probably de facto parkland, similar to the Chernobyl Exclusion Zone. So my Wild Mass Guess is that outside of the cities, the world looks more like The Last of Us then Mad Max.
Not so much, considering how tame they are in comparison to M-Rated and AO-rated games today.
Not only to mention, for the film, after one minute of playing the wrong game, their avatars fall through the ice. So, even if those titles were included, it would be a short time playing them. So, nothing to really feel sorry about.
Also, people are forgetting the fact that they didn't even get all the way through the list. Keep in mind, IOI is choosing options that Halliday most likely would have gone with for their choices. And seeing that Halliday doesn't seem like the kind of person who'd play those particular games, there's a good chance that IOI would have kept picking games Halliday would have more than likely played before even getting to the adult games.
Finally, the big one that no one mentioned: the games' graphics are so basic, they're basically akin to stick figures in comparison to something nowadays with highly detailed models.