Ascend to the Citadel. Then find out what is under it.
First steps, core mechanics and introductory quests
Configure controls and familiarize yourself with basic mechanics before proceeding.
Advance through the main campaign while watching for cutoff points
Cross the climactic point of the main storyline to complete the game.
Side objectives that must be cleared prior to the story climax
The knight and his mount in the Whispering Vaults, an optional bout. ⚠️ Skip it and it is gone for good: Nintendo Life’s boss list marks the fight act 2 only, and once act 3 begins it does not return, black-threaded or otherwise.
The cartographer. Once her Trail’s End wish is done she offers a duel; the Throwing Ring is the wish’s reward, not the fight’s. ⚠️ Skip the duel and it is gone for good: it is act 2 only, and can no longer be fought once act 3 begins.
Gathering remaining collectibles and securing 100% completion
Every boss in act order with where it is, whether the story needs it, and what it drops. Sources disagree on the total: the Hollow Knight Wiki counts 47 with repeat fights (43 without), Nintendo Life lists 45, Fextralife 44 plus four mini-bosses and PCGamesN 48; this list has the 46 fights the wiki names, leaving out a second Skull Tyrant that only appears by chance.