I have not finished the game yet, but I can still tell that this game is one of if not the best games I have ever played, the world, the characters, everything about this game is amazing and it combines a sense of wonder and mystery perfectly, this is accomplished with the amazing music and world building the game has, for example, in the area the Fungal Wastes, the music used there sounds like it would be used in a documentary, following something small in a big and dangerous world, and in that same area with the cheerful, somewhat goofy music, you can find a giant dead mushroom creature, which makes the player think 'Why is this here?' 'What caused this to die?' 'Is Elderbug single?' But the game never tells the player these things, it's up to them to figure it all out.
Hollow Knight takes the 'show don't tell' way of storytelling and runs with it completely, the game tells you basically nothing, all you really know is that: You are bug dude, you have to kill bigger bug dude, because bigger bug dude is bad. And you have to try and put pieces of this broken story and broken world together, the developers have even said that there are multiple endings, but none of them are canon, or maybe all of them are canon, it's up to the player to interpret it how they see fit, and i think that is an amazing way to tell a story.
Overall this game is amazing and I can't wait to see what Team Cherry will do with Silksong, if it ever even existed.