Ug, i'm a nintendo fan.
Tell me...
Zelda engine is the first engine where everything lifes. My natural language isn't English so I'll do my best. I also give you a few examples
It's the first game with real full weather cycle where everything change on the fly.
All objects in the game response on your behaviour and its not prefab made like all other games. Using everything as a weapon, moving things and solving puzzles by that not using always one solution. Even enemies can use everything in the world, don't going to spoil anything. It's first open world where you are free to go with no real boundaries. Climbing on every mountain you'll see. Small things like the fire goes depending in what direction the wind blows. There are many things more to let you experience all the freedom. Beside mmo that doesn't use this kind of physical engine, you don't have any game that doesn't push you in some direction / path. With this zelda you could even go directly to the end boss, not that you'll will survive. This kind of experience isn't done before. I hope many more games like this will come.