I beat God of War before most people got to play it. That's one of the side effects to my job; I play things ahead of time and while folks are drinking deep on the ongoing conversation, I've likely moved onto the next game. I took Kratos and Atreus on their journey across the realms of Norse mythology and brought them home again. It was a satisfying ending that promised something more.
The end of the story wasn't the end of the game though.
Part of what I enjoyed about God of War was how it told its tale. Kratos himself is rooted in Greek mythology and that carries forward in the new game despite the change to Norse myths. Greek myth is full of heroes—and I say heroes in the loosest sense, as many of them aren't kind or good people—who have a simple goal, but tend to face a series of unrelated trials along the way. It's a structure that can sometimes drag on, leaving you wondering if the protagonist will ever achieve their ultimate, sometimes mundane goal. (See also: the old Hulk TV show.)
For example, there's one Greek myth that's rather close to home for Kratos. The Twelve Labors of Hercules are penance for the Greek hero's crime of killing his wife and children, something that also kicks off Kratos' desire for revenge. Hercules kills his family and Apollo tells him to serve the king of Mycenae for 12 years.
What follows are 12 feats that are completely unconnected, except for the fact that Hercules was the one who completed them. He killed the Nemean Lion and the Hydra, cleaned out the Augean Stable, stole the belt of the Amazon queen and the Golden Apples of the Hesperides. His final Labor was to capture Cerberus, the guard dog of hell, which he used to threaten the king of Mycenae for his freedom. Avid God of War fans will note that Kratos also did some of these, leading many to believe that he was a version of Hercules, right up until Kratos fought him in God of War III.
You'll see similar storytelling parallels in other Greek myth. The Odyssey is all about the random journeys of Odysseus, who had a bad time trying to get home after the Trojan War. Jason, leader of the Argonauts, wants to regain his throne by obtaining the Golden Fleece. Perseus just needed a gift for the guy he wanted to keep away from his mother. (It's a weird premise.) This idea of continuous trials and feats extends to Norse mythology, with the tales of Thor, Sigurd, Brynhildr, and more, though many didn't have a single aim for their adventures.
God of War leans on this idea with Kratos and Atreus' journey. The impetus is a simple one, taking the ashes of wife and mother Faye to the highest peak in all the nine realms. Getting there isn't that simple though. Father and son have to deal with the attentions of Odin's son Baldur and cross the Bifrost to reach other realms. They have to flee Helheim, the realm of the dead, and navigate the war between Light and Dark Elves in Alfheim. The pair kill the dragon Hraezlyr, the king of the Dark Elves, and even the sons of Thor himself. All of which are merely semi-unrelated obstacles in their quest to spread Faye's ashes.
Ultimately, they do, at the peak of the highest mountain in Jotunheim, realm of the giants. And then they go home. Their actions have set dire things in motion, but the adventure here had one aim and it was completed.
Like the best Greek myths, the adventures aren't done though. The trials of Kratos and Atreus continue on. Two of the realms you can unlock never have to be touched to beat the game. The burning core of Muspelheim, realm of fire, has the pair using their mighty combat abilities to finish the challenges of Sutr. Its opposite is Niflheim, a ghostly realm of mist, where you can wander through the cursed fog of Ivaldi's Workshop.
Both realms hide one of the lost Valkyries, a series of eight warriors trapped within the realms in physical form. These Valkyries are hidden, imprisoned by Odin for their transgressions against the king of the Norse gods. By fighting and killing them, you free them from their imprisonment, taking their helmets as trophies. Once Kratos and Atreus defeat the other eight, it awakens Sigrun at the Council of Valkyries. It is the hardest boss fight, coming only after you've completed some of the most vicious challenges God of War has to offer. Talk about Labors!
Kratos and Atreus can also find three dragons anchored to Midgard. These dragons offer Dragon Tears, powerful items needed to upgrade the powerful Shattered Gauntlet of Ages relic. One you gain by killing Hraezlyr, while you get three more for freeing Fafnir, Otr, and Reginn, who are guarded by hordes of enemies. Yeah, you free huge monstrous dragons in order to power up a rough reference to Marvel's Infinity Gauntlet, one of the strongest talismans in the game.
All of this is incidental and unconnected to the story of Kratos and Atreus. They're very big, mythical moments—you free Fafnir and fight Sigrun, major figures in Norse mythology—but they don't really matter to the story of God of War. They're just these huge feats that Kratos and son did while jaunting around the Nine Realms. That's really the essence of old mythology, heroes doing these amazing things because they could. The mythology involved gods and men that might as well be gods tearing down whatever lay in their path.
God of War's ties to that type of storytelling will likely increase in sequels given the game's ending. Kratos' wife Faye is revealed as Laufey, which gives avid fans of Norse mythology a hint of who Atreus may be. And killing the sons of Thor has not only brought on the attention of the God of Thunder, it might also call Odin down upon their heads. The ending of God of War is cathartic, but it's one that points towards everything ending in tragedy.
Because that's the other side of many tales in Greek mythology: the tragic end. We just don't know when Kratos' will come, though a mural towards the middle of the game points to Atreus being the one to finally kill his father. That's later though. For now, the adventures of Kratos and Atreus stretch on in further labors and trials. Ones that mere mortals among us are still working to complete.