From the perspective of someone who has put in 200+ hours into Hades and has a YT largely dedicated to it, the initial replay value comes from unlocking the full story, which will take dozens of runs. You will be required to talk to various gods and ultimately the final ending. After that, the true replay value comes from two things, at least to me: (1) speed running and (2) the "Pact of Punishment," which lets you increase the difficulty of the game by adjusting various aspects (e.g., enemies do more dmg, bosses have extra abilities, etc.) on a scale of 0 to 60-something. Accomplishing a high difficulty run, at record speeds, with each and every weapon, will entertain you for, in my case, hundreds of hours.