To avoid whiting out the page, expect spoilers to be unmarked. This is your only warning.
When Gary is trying to convince Andy to go on The Crawl, Gary's non-sequitur quipping and general silliness actually is getting through to Andy, evidenced by his sigh which is a mixture of fondness and annoyance (along the lines of "I know I'm being manipulated and it won't matter - I'm going to cave."). The only thing that restores Andy's will is Gary blithely asking if he has to okay it with wife. Andy is separated from his wife, and Gary uncharacteristically has pressed a Berserk Button.
The Network's argument of "look at all this technology? Don't you love it? Don't you love us?!" was never going to work on Gary. He has the same car from when he graduated high school (20 years before), still uses cassette tapes and uses a 10-year-old cellphone (which doesn't even have a colour screen). He barely benefited from their technological advances. Which is why, when the Network asks Gary if he's noticed the proliferation of technology, his response is "nope". It also fits with the theme of his being stuck in the past.
The name of the town, Newton Haven, is as close to "Network Heaven" as you can get without being obvious about it.
The Network's attempts to silence the Five Musketeers get more and more over-the-top as the pub crawl progresses, starting with being pulled over by a cop, and leading to them being swarmed by a few teenagers, then an angry mob, then a gigantic Mecha. The Network's defence becomes more and more outlandish the drunker Gary and his friends get, because if they live and run away, no-one would ever believe that five drunks stumbled upon a genuine galactic conspiracy!
Glass 12 is found already poured out for Gary when he enters The World's End as one last hope that he won't find the elevator to the underground base, which is triggered by the beer tap.
If you look at the walls flanking the entrance, they have blue signs that say "WELCOME" and "JOIN OUR CLUB". Odd thing to put for people going out...unless it's there to foreshadow to the audience.
As the conspiracy unfolds, mobile phone sounds can be heard in the background, because the gang is searching for the Network.
All of the pub's names refer to crucial parts of the plot that occur within those pubs:
The First Post: where the story begins.
The Old Familiar: where the gang meet Oliver's sister, Sam. Not to mention the pub is mostly similar to the previous one, making it very familiar.
The Famous Cock: the first pub where Gary is recognised... because he was barred, presumably for being a famous cock.
The Cross Hands: where the gang learn of the plot, get angry (cross) with Gary...
...but then resolve to see through the pub crawl at The Good Companions.
At The Trusty Servant, they meet Reverend Green, who tells them more of the conspiracy, and gets killed for his troubles.
At the Two-Headed Dog, they fight the twins who are, at one point, four-legged.
At The Mermaid, they are lured away from their mission by the siren-like Marmalade Sandwich...
... and discover the true nature of the Network's Hive Mind at the Beehive.
Gary (The King) then attempts to finish the crawl alone at The King's Head.
Steven drives The Beast through the Hole in the Wall...
At the crawl's beginning, Gary chides Andy for ordering water, uttering the nonsensical statement, "did King Arthur order waters after the Battle of Hastings?" - to which Andy replies that ordering water in a pub full of rugby lads wearing warpaint takes balls. At the end of the film, Gary (a King), following a battle against the Network, orders five waters in a post-apocalyptic pub full of skinheaded, armed rugby lads - all wearing warpaint.
"Look at the town in it's original colours, cos tonight we're gonna paint it red!" At the end of the film, Newton Haven is engulfed by a giant, red fireball.
As far as just how stuck in the past he is, it's very telling that Gary can barely keep the current details of his friends' lives straight but he is the man to ask about some random event in 1988 or the precise origin and etymology of an old between-friends slang term like "let's boo-boo."
Gary King regards himself as something of a town legend - but none of the blanks remember him. It's later revealed that blanks who are willingly assimilated get to select what memories they keep. Apparently, nobody wanted to remember Gary King. Despite Gary's claims, it seems the town was happy to forget him.
And when the group enters the fourth pub the bartender instantly recognizes Gary has been banned even though that was a single incident 20 years ago? It's because those memories are now part of The Network, which does recognize Gary and is trying to stop the pub crawl from continuing.
Oliver, who never takes his bluetooth headset off and is visibly the most attached to modern technology, is the first of the Five Musketeers to be captured and assimilated by the Network. This is contrasted to Gary, who owns an outdated cellphone, has no idea what "WTF" means, and is the biggest enemy of the Network.
It seems odd at first that a group of middle-aged people are so good at destroying robots. The Blanks, however, weren't designed for combat, but for deception and enticement. The Network may have deliberately sacrificed the Blanks' durability for their being easy to build and re-build. Furthermore, Andy is still a rugby player and very athletic. Steven is dating a fitness instructor and seen working out. Gary has Le Parkour skills from his teenage years and hasn't lost them. The only ones without a justification are Pete and Oliver, who fare the worst in the fights and end up becoming Blanks.
It must also be pointed out that the reason the Blanks are so fragile is that they are made out of cheap material so they can be reproduced as soon as possible. Another Mr. Shepherd pops up only five minutes after being shattered by Andy. Their main physical way of dealing with interlopers is a) We Have ReservesZerg Rush and b) a giant, slow moving robot.
For all his hard work, Gary gets the ultimate Manchild fantasy, he's sword swinging, Badass Longcoat wearing, Action Survivor wandering the postapocalyptic wasteland with his childhood friends.
At the beginning of the final confrontation, the Network refers to Gary as "Gary King, of the humans." A subtle shift in pacing the next time he says it makes it sound more like "Gary, King of the Humans." Which is fairly appropriate, considering he's more or less singlehandedly deciding the fate of the entire Earth at the time.
Gary is a man who refuses to grow up and leave the past. At the end of the movie, he decided for the whole planet to never advance, and it became stuck in the dark ages.
Why did The Network choose The World's End as its main hub in Newton Haven? When Gary and Andy are descending on the platform, some brewing equipment bearing The Network's logo is visible behind them. The World's End must be a brewpub, and The Network is using it to produce the blue liquid found inside the Blanks.
The five are called the Five Musketeers, when it's mentioned in the film that there were only three, four including d'Artagnan. Who did the musketeers serve? The king. So you have four musketeers and the king.
Gary makes a remark in the same scene about how it should have had five musketeers, since then two could get killed and then there'd still three left. Later in the film Oliver and Peter are both killed off and replaced by blanks, leaving only three of the five musketeers to make it to The World's End and confront the Great Intelligence.
No matter what, The Network's plan would have failed, since Gary pointed out their plan was failing anyway: replacing 97% of the population of the 2000 towns they were controlling with Blanks was kinda defeating the point if their goal was to uplift the Human race.
The Network really does leave humanity "to [their] own devices": every device they made before the Network started interfering (which isn't all that much).
Shane Hawkins, even as a Blank, could have wiped the mat with Peter, but allowed him to beat him up as a trap. The Blanks knew it was a temptation Peter couldn't pass up.
Sort of related, why doesn't Shane Hawkins recognize Peter instantly despite the bullying? Well, given how terrible the bullying was, most of their interactions were Shane bullying Pete, and Shane most probably opted to leave the memories of his bully-days behind.
More like Fridge Sadness. The reason Gary hasn't spoken to his mother in months is because he doesn't want to face having to discuss his suicide attempt with her.
How did Steven make it to Andy and Gary after what happened at The Hole in the Wall? He was not present with the others at The Mermaid when the Marmalade Sandwhich got their DNA, which was required in order to transfer their consciousness into one of the Blanks, Thus, he was able to escape without being taken.
Also doubles as a Tearjerker of sorts. When the musketeers are in the fourth pub, Shane Hawkins, a childhood bully to Peter, comes over and asks if he can take one of their chairs. He doesn't recognise Peter, and the others let him take the chair, but Peter immediately recognises him as the terror of his youth. He's visibly uncomfortable about seeing him, and when the others press him for information about exactly why, Gary is the only one who actually reasons with him, and tells him that bottling up past trauma can lead to unhealthy coping strategies. First, this something that Gary King would NEVER know to say (he's hardly likely to be reading psychology textbooks in his spare time or anything), and it also serves a double purpose. It tells us Gary actually has some experience with this kind of psychology, hinting about the revelation that he himself bottled up his past misery and pain resulting in his suicide attempt, and he undoubtedly heard this phrase several times from therapists. But it also shows us that Gary recognised the same behaviour in Pete and wanted to stop him from making the same mistakes that he did too, trying to help Pete overcome his own pain while burying his own. And just to hammer it home, right after Gary says thsi to Pete, his eyes flick around the group and he adds '...apparently', as if trying to cover up that he knows more than his friends would expect of him. Gary recognised Pete's behaviour, warded him off the destructive choice of burying his feelings, and then buried his own past by claiming he had no idea what he was actually talking about, despite knowing full well what he was doing.
When Gary tries to convince Oliver to come, Oliver claims that he probably has a doctor appointment at that day, whereupon Gary jokingly says that it's with Dr. Ink. In the end they really do run into some...blue-inky guys.
The boys all have last names that correspond relatively well with some medieval occupation or position - King, Prince, Knightley, Page, Chamberlain - which ties in well with the Feudal Future they end up with.
All of the scars that the boys display to prove that they're human came from Gary. No wonder they're sick of him.
Why does Gary opt to bash his head against a pillar to show it doesn't break instead of pulling up his sleeves and show a scar on his elbow? Because if he did they would see the scars from his suicide attempt and he does not want to talk about it.
Gary teaming up with the blanks at the end makes sense when you consider the fact that he hung out with a couple of weedy, nerdy kids in his younger days. It seems Gary's always had a bit of sympathy for the little guys, regardless of who they might be
Tying into the second pub crawl being a repeat of the first, either in a literal sense or fitting into Gary's description of it at the start of the film, you would think that the parallel would break down due to the driving force of the plot being that the second time around, the group are going to do what they couldn't initially, hitting the last three pubs. It's fitting, then, then by the time the divergence occurs, any semblance to a pub crawl has completely disappeared - Gary is racing between each pub, necking a pint and immediately leaving, with both an army of Blanks and a highly concerned Andy on his tail.
Whilst those who fight The Network are normally composted and replaced, it's also possible that others who resisted could have received the same offer as Gary — effectively giving up their bodies and personalities to be mulched into compost — in exchange for eternal youth and a thimble full of happy memories.
There is no way that the total collapse of high-tech civilization on Earth would result in "a few" casualties. With distribution networks, power grids, communications systems, and basically everything needed to, say, keep a city of 10 million people fed goes offline, those people will eat up everything they can, rather quickly putting each other on the menu as well. 6 billion people dead within a few months would be about the most optimistic outcome here. With that said, the death toll only includes humans, not blanks. Also, Andy says that they don't know how many really are dead. A few may well just be the people he knows.
That's exactly what it is - Andy says "I knew a few of them," not "only a few of them."
As noted by Gary, he's only determined to finish the Golden Mile because he didn't the first time, and his previous run was the last time he was ever truly happy. In the conclusion, he also explains that the Golden Mile is all he has, and that support he received doesn't help him; in other words, the pub crawl is either a final attempt to move on and find a reason to live, or it's One Last Field Trip before Gary attempts suicide again (the pub crawl itself could've been his attempt at suicide via alcohol poisoning).
After the Network releases control, the blanks repair none of their injuries (e.g. Blank!Oliver's head). Given how fragile they are this means they are going to eventually collapse from small accumulated injuries.
The one blonde Blank seen frequently in the background, pushing a pram/stroller. From what we've seen, the youngest looking Blanks look about fifteen. What happened to the original's baby? In fact, what happened to the empties' children if they had any? Does The Network wait for them to grow up to be considered useful or do they get mulched when they misbehave?
Humans turned into Blanks are mulched and "recycled". There are recycling bins throughout the town bearing the Network logo. Late in the film, the number of bins increases dramatically, as does the evident number of Blanks. Do the maths.
Sam's childhood crush Adrian Keen appears in The Mermaid in order to distract Sam or tempt her into staying but she is horrified by his appearance because the real Adrian died in a motorcycle accident years earlier. Since he appears the same age as the main characters then it can be assumed that he was made into a blank when he was forty or had enough DNA on file to accurately guess his age during the time of the event. Since the real Adrian died in an accident, it's not hard to assume that he tried to escape one of the Blank's bases to warn the rest of the world but died when he drove too fast during his escape. Or the Blanks caused the accident.
Except the fact that Sam mentions that the real Adrian died in Italy, rather than southern England.
The Network did say that they didn't just operate in Newton Haven and that they are responsible for humanity's technological revolution.
A few drinks into the pub crawl, Gary goes to the toilet. He gets very angry at a teenager brushing him off, starts fighting him, and throws the kid down so his head bashes into a urinal. Up until this exact moment, when the robot's head pops off and blue ink sprays everywhere, Gary had every reason to believe the teenager was human.
To be fair it did look like it was an accident that the kid's head hit the urinal as they were falling.