generally when people say that it's about the level of freedom you're given and the level of respect the game shows the player in a lot of aspects in terms of just leaving you to your own devices and trusting that by doing you'll figure things out and have constant discoveries. things like having towers only show the topography of the map rather than revealing all the points of interest, the go anywhere do anything progression, the level design and world geometry combined with the different mechanics like climbing and gliding making a more engaging and engrossing play experience, and the physics and chemistry engine leading to exploration and discovery with the gameplay systems along with the exploration and discovery in terms of traversing the map. there's a lot of things in the game that have a sort of first souls-like effect on the player where preconceived notions and habits get challenged and there's a re-acclimation period with what the game is, what you can do, and how you can approach all the different scenarios.
