Acceptable Religious Targets: This is a Buddhist story written at a time when Buddhism's old religious rival in China, Taoism, was falling out of favour. The novel makes some vague noises about interfaith respect and tolerance, and Lao Zi, the deified founder of the philosophy, is treated with respect (even if Wukong does outwit and humiliate him unusually often for someone of his stature), but it's still rare to find a Taoist priest in it who isn't both (a) a power-mad Evil Sorcerer and (b) a man-eating demon disguised as a human, though many of their more-horrible deeds (carving out the hearts of ten thousand innocent children to make an immortality elixir comes to mind) were based on actual purported histories of the time.
Awesome Ego: Sun Wukong's ego reaches the heights of heaven, and his cockiness touches the bottom of the deepest sea.
Crazy Awesome: Many of the characters in the Tsai Chih Chung comic adaptation.
Ensemble Darkhorse: The White Bone Demon appears to be this; despite being a demon with a rather ordinary skill set (shapeshifting) and pretty much zero fighting ability, the arc featuring her is one of the most well-known in all of China, and the subject of numerous operas and television specials.
Fanfic Fuel: The titular journey to the west. As any TV adaptation with original stories can tell you, the road trip-style premise allows room for plenty of self-contained adventures Sanzang and his disciples might have gone on in their travels.
Fridge Logic: It is shown and stated several times that Sun Wukong is able to cover hundreds of miles in just a few seconds with his somersault cloud, which makes you wonder why he doesn't simply carry Xuanzang to the Wesern Temple by cloud and save them the long journey by land. This is lampshaded by Zhu Bajie in chapter 22, after which Sun Wukong explains that it is impossible for mortals like Xuanzang to travel by cloud because their mortal flesh and bones are too heavy for that. Also, Xuanzang is the only one that the Buddha will give the scriptures to, so there is no point in Sun Wukong traveling to the temple by himself and ask for the scriptures on Xuanzang's behalf. But in any case, the whole point of the journey is for Xuanzang to go through lots of dangers before getting the scriptures, so that people back home will be properly impressed, and so that it will be symbolic of a pious person's journey through life's temptations etc.
Genius Bonus: General Three O'Clock and the Special Dweller's names hint to their identities. Three O'Clock is the hour of the Tiger, while Special Spotted Dweller is a Chinese epithet for bull.
Mainstream Obscurity: Easily the most famous of the 'Four Great Classical Novels', it has spawned endless derivative works and is popular throughout East Asia but it's rare to know people who have actually read the book. Most East Asians are only familiar with it through Pop-Cultural Osmosis and television adaptations of the story. Most Westerners will only be vaguely familiar of it through Dragon Ball.
Values Dissonance: A lot of motivations and justifications for the heroes' behavior look definitely odd to a modern reader.
The fate of the villain of Chapter 84 can be seen as this for many modern western-minded readers. For those who don't know. in that chapter, the pilgrims come across a country led by a king whose goal was to kill 10,000 Buddhist monks in his kingdom because of wrongs done to him by Buddhist monks in a past life. In the end, he is changed into a monk and redeemed, with that chapter demonstrating the forgiving power of Buddhism. However, given the scale of his crimes, most modern readers would find it unrealistic and expect him to be killed instead.
Bajie joins The Team because his mortal in-laws end up hiring Monkey and Xuanzang to exorcise him from their farm and chase him away from their daughter, Blue Orchid. However, Bajie legitimately married Blue Orchid and did so with their permission, and while he is quite a glutton (as he himself admits), he's also a very hard and diligent worker who more than earns his keep by his labors. As he notes to Monkey-in-disguise, he cleans the ground, drains ditches, carries bricks and tiles, builds walls, plows fields (pulling the plough singlehandedly at that), plants grain and generally improves the farm, with even his in-laws admitting that he does his labors, which is why they were happy to take him in as their son-in-law in the first place. So why do they want him gone? Because it's undignified to have a monster as a son-in-law. This makes perfect sense to Chinese and Japanese cultures, even today, but modern Westerners tend to see them as Ungrateful Bastards engaging in Fantastic Racism: he's being cast out, despite being everything a farmer could want in a son-in-law, simply because of his race. note Incidentally, this may be why this aspect of Bajie's story is almost never adapted straight. For example, in Monkey, Bajie is to be exorcised because he's given up being a dutiful son-in-law to instead become a wastrel who spends his days eating, drinking and picking fights. In Dragon Ball, the Bajie-expy Oolong is an enemy because he keeps kidnapping girls (all of whom end up pushing him around and bullying him, to the point he's happy to give them back) and the whole "in-laws call for exorcism" angle is dropped entirely. Admittedly Bajie isn't entirely innocent — by the time Monkey and Xuanzang come along, he's keeping Blue Orchid locked up in his private room and not letting her parents see her. But it's never clarified whether he's doing that because he's just an asshole or if he's only doing so because he's angry at how, after having welcomed him into the family, his in-laws have turned on him for his supernatural nature.
As mentioned under Disproportionate Retribution on the main page, Shā Wùjìng receives 800 lashes, is exiled from Heaven, is transformed into a demon, and has to spend the rest of his life hiding in a river to avoid a magic sword that will stab him daily in the chest, all for the heinous crime of...breaking a cup or a vase. A little extreme but not unreasonable in the time-period for when it's set (porcelain, crystal and jade being very difficult to work with, so literally more precious than gold), but horrifying to a modern age audience.