Definitely a system-seller. For a Zelda game, it does so many things right in its first entry into a sandbox world: Few elements that feel random, making use of the map marking function actually effective in exploring. Right from the Great Plateau, you are given all you need to tackle this vast world -- can even challenge the last boss if you want to. 90% of the gameplay is trial-and-error exploration and no longer the formulaic, linear dungeon-crawling path.
For its first entry of the franchise into having the supporting characters have full VA is decent enough. Of course Mipha and sometimes Zelda VAs really need to get some energy into their characters, but they all fall into cookie-cutter personality archetypes due to the small roles they play(Zelda being an exception of course).
Probably one of my favorite qualities of this game is the physics engine and how much it contributes to your gameplay experience if you choose to be creative, but doesn't shove it in your face nor does it exist just for the aesthetic. Create a seesaw by putting a metal door on a stone! Get your own "airship" by simply exploiting Octarok balloons on rafts! This is definitely a great game with how it welcomes the player and his/her ideas toward progression.