Last night, I went to watch Nolan's adaptation of Odyssey. Homer's Odyssey has existed for over 3000 years, but I suppose it's still worth pointing out that there's lots of spoilers here.
First and most important, no I don't give a single shit about the "controversial" casting choices. That was a manufactured racist and transphobic outrage. Helen was in like 3 short scenes. She was never depicted in Troy (her only depiction in the story) and was ultimately a tragic character.
I'll refer to Homer's tale as "the story", and Nolan's version as "the film".
Let's start the actual review with my biggest disappointment in the film and the first part of the story: the Cyclops scene. In the film, as in the story, they realize too late that the cave is occupied. The reason it was impactful in Homer's tale is that Odysseus violated Zeus' Law inadvertently by killing the Cyclops' favorite sheep before it returns/awakens (interpretations vary here). The tension in the story comes from Odysseus and the Cyclops negotiating, and Odysseus outsmarting the Cyclops by slipping Lotus fruit (more on that later) into some wine before giving it to the Cyclops. The lotus fruit is the reason the Cyclops fell asleep before it could kill them all in the story.
None of this preamble exists in the film, the Cyclops just shows up and starts killing them. Additionally, in the story when they stab the Cyclops in the eye, they learn that it's too dangerous to kill the Cyclops because it's siblings lived deeper in the cave and investigated the screaming. In the film, the Cyclops is alone. The high point of this scene in the film is when they escaped the cave, which follows closely to the story.
The next part of the story is meeting the god Aeolus. This part is very abstracted from the story, but I thought it was an extremely interesting interpretation. In the story, Aeolus' island is floating in the sky and he gives Odysseus a bag of winds to escape Poseidon's storm. The bag gets opened, the fleet gets pushed by the winds towards the land of the giants, and then Poseidon drowns most of his men and destroys all the other ships in Odysseus' fleet.
In the film, they approach an island surrounded by a dense, low fog. When they meet Aeolus, he gives a bloodcurdling scream which summons forth an army of giants that kill most the men and destroy the other ships. This is a truly creative way to depict this scene, and excellently portrays destruction of his men without explicitly explaining what's occurring in relationship to the story.
The 3rd conflict in the story is meeting Circe. This scene in the film easily outdoes the story in my opinion. In the story, Odysseus decides on his own to stay back while a landing party goes to the island. Eurylochus returns shortly after leaving, and tries to convince Odysseus to leave the men behind and flee the island. He refuses, which inspires Hermes to give Odysseus the Moley flower to counter Circe's magic. Odysseus and Circe stalemate, and she decides to help him instead of continuing the standoff. Circe reveals that a group of previous travelers raped and killed several of the dryads she was protecting, which is why she transformed his men.
In the film, Odysseus is forced to remain behind because the crew no longer trusts him to act in their best interest. All of his men get turned to pigs, so he has to figure out Circe's tricks on his own and without the aid of a god. I love this change, I've always felt like the Moley flower macguffin was too similar to the lotus fruit against the Cyclops. I know that it's a product of ancient Greek bardic tradition, but it just doesn't work for modern stories. The magic was also extremely visceral, and displayed the cruelty in her actions. Overall, an incredible scene.
Next up is sailing the river Styx to meet the dead prophet. I'm also going to combine this part with meeting the sirens, Charybdis and Scylla, and landing on the island of the Apollo. All 4 scenes are very close to the story, so there's not much to compare. I don't recall Odysseus talking to anyone other than the prophet in the story, but he was absolutely haunted by his dead crewmen while searching for the prophet. Being chased back to the ship by the summoned dead in the film was cool though. The siren scene was cool. Staying true to the story for the sirens would have been a mistake, as Odysseus talks to the sirens by reading their lips to learn how to get to Ithaca. Making it a silent scene was perfect.
Charybdis and Scylla was flawless in the film, Scylla was perfectly mysterious despite seeing it clearly in daylight. I kinda wish the mutiny after this point was more clear, but otherwise this scene was so good. Absolutely no notes about the murder of Apollo's cow.
In the film, we first meet Odysseus on Calypso's Island. I was kinda bothered that her island was mostly barren. In the story, she lived on a magical floating island that grants immortality to humans, and was described as a lush forest. I also didn't particularly like that the film depicted Odysseus as being a lotus eater, but it fit with the tone of the movie. Honestly there's not much to say about these changes, it just bugged me because it's related to the cyclops scene. This is the part where we talk about the lotus fruit.
In the story, Odysseus first lands on an island which only has lotus fruit for food and a group of lotus eaters, which is how he both learns of the cyclopes cave and gets the lotus to lace the wine. It annoyed me that Odysseus was a lotus eater, because in the story we're told explicitly that lotus is so addictive that you will never break the addiction and it completely consumes your mind. We get some of that in the film, but Nolan breaks this important rule in the story. It doesn't bother me too much though, because the film went to great lengths to give the appearance of magic while maintaining a plausible semblance of the mundane. Calypso controls Odysseus with magic in the story, so I understand why Nolan used the lotus as the method of her control. The truly interesting thing about the lotus though is how it was depicted.
The truth is that it's a complete mystery what the lotus actually was supposed to be in the story. It's unknown if it was a different name for a fruit we know, a fruit that went extinct, or a completely fictional fruit. Instead of the lotus being a fruit in the film, it's a fictional depiction of a lotus flower. The reason this is interesting is because the symbol of the lotus flower represents rebirth and enlightenment. I think what this is representing in the film is Odysseus realizing he cannot protect everyone, and that fighting against the Fates is ultimately impossible.
Last but not least in the story is Odysseus' homecoming. There was a lot of hand waving by Homer about reaching his palace from Calypso's Island, but one detail was Odysseus and Poseidon settling the feud caused by blinding the Cyclops. I love how this was depicted as Odysseus accepting fate and giving his trust to the gods, which is rewarded by the water washing over him, but not drowning him or harming him when he reaches Ithaca.
A detail that I always get miffed about when it's excluded is the discus throw during the trial of suitors, mostly because it's truly hilarious how much he outclasses the suitors in the challenge. Despite being outclassed in this manner, they still find it ridiculous that Odysseus could string the bow. I kinda wish the fight was more spread out through the palace like in the story, but that final fight was awesome.
Overall, I'd consider this film to be very faithful to the story. It's an excellent retelling, and I would recommend it.