Hollow Knight’s Dream Nail — obtained mid-game — allows the player to read the thoughts of NPCs and enemies. Most players use it on living characters. Far fewer think to use it on the corpses scattered throughout Hallownest.
The deceased NPCs have unique thoughts accessible only through Dream Nail on their bodies. Some are mundane — the last thought of a dying soldier. Some are devastating: a Husk who died dreaming of a return to the White Palace, a Baldur who saw the infection coming and stayed anyway.
Using Dream Nail on the Hollow Knight’s chains — not the Hollow Knight itself, but its restraints — reveals a single line that reframes the entire boss fight. Team Cherry placed the line knowing only players who thought to check the inanimate objects around the boss arena would see it.
The game’s lore is accessible through about a dozen different systems: item descriptions, NPC conversations, environmental design, hidden rooms, geo amounts, and Dream Nail dialogue on objects that appear uninteractable. No single system gives you the full picture.
The detail work the devs put into areas most players never visit is what separates great games from good ones.
I’ve put 200 hours into this game and never caught this. The developers really reward the obsessive players.