Zagreus, god of who the fuck even knows, son of Hades, god of the dead, is trying to escape his father's realm. His father does not like this, as he is very adamant about not letting anyone escape the Underworld, even for extremely good reasons such as "I want to meet my mother" or actually "the Underworld is TERRIBLE and BORING someone LET ME OUTTTTTT". So Hades has put a number of obstacles in Zagreus's way, including: floating skulls, witches that shoot balls of energy, magic crystals that shoot lasers, Zagreus's ex-girlfriend, jumping explosive skeletons, sentient falling boulders, lava pits, the undead skeleton of the infamous Hydra with all of the heads this implies, various shades of the erstwhile heroes of the living, pink spheres that generate butterflies, traps, and ash urns that shoot missiles.
These things, while very deadly and harmful, can do nothing to break Zagreus's spirit. They can break Zagreus's bones, sure, and kill him many times over, but he gets better, and comes back for more.
He has killed his ex-girlfriend a few times and boy howdy if she was already pissed at him over their relationship the whole murder thing did not help matters; some Nectar of the Gods has been offered as a peace gesture but she has not taken it that kindly either. He has defeated the remains of the Lernaean Hydra a couple of times, even though it is a very sharp Hydra with lots of bony apendages. He has walked through the idyllic fields of Elysium, which are filled with traps and murderous ghosts and all in all much less idyllic than he had hoped.
And he knows the gate is right there, it's close, he can feel it in his bones. There is only one last challenge.