I love that Hollowknight keeps players in the dark, sometimes literally. You are thrown into a complex story that is up to you to decipher (it's worth deciphering because the story is extremely intriguing). There's mystery around every corner, a natural map that makes you think back on different puzzles and areas that you couldn't get to in the beginning.
Every enemy and boss has unique attacks and styles that perfectly allign with their respected areas in the world.
So many different ways to progress through the game makes every playthrough exciting. And it all leads up to an ending that you get to choose.

Exploring Hallownest for the first time was an experience I can't forget. Using stag stations to get around added to the immersion of the game and made it all seem bigger. Adapting to different enemies while trying new charms kept the game fresh throughout the entire playthrough. Another thing that kept the game fresh was that I was never stuck on ONE objective. I could collect dream essence, try a boss fight that I couldn't defeat before, upgrade my soul/health, or even find new charms. It's impossible to predict what adventure will happen next. And all of this happens in a polished, charming art style that never gets old.