The Legend of Skyrim: Breath of Assassin's Creed? Is that Ezio climbing that temple wall? Is that Connor hunting down that buck? Nope... It's... Link?
I watched pretty much the entire stream earlier, and this new Zelda appears to be taking elements from every popular open-world game over the past few years and jamming it into a Zelda game. How I feel about it is unknown. Depending on what they decide to do with this, I may be overjoyed beyond belief, or sorely disappointed depending on how lively they make the NPCs. They've clearly done an excellent job with the wilderness, and how the wild animals (and even enemies) interact with each other (Bokoblins hunting down bugs, boars, pheasants and other wildlife from food), as well as how Link interacts with them as well, which brings me to my next point.
It was interesting to see how each different person who played the game from Link's awakening in the cave took drastically different paths once they emerged onto the Plateau, and all of them managed to still find things to do, and weren't limited on what they could/couldn't do. Whether they decided to jump off that cliff in the beginning, run down the path to the right, or scale the cliff and venture into the frigid mountains to the left was completely up to them, and they weren't punished at all for doing so, they even progressed regardless of where they went in some way (Shrines, hunting spots, areas rich with resources, etc). I'm personally a big fan of an opening like this, where the player is quite literally thrown out into the wilderness without silly tutorials and hand-holding that occurred in previous Zelda games. Another interesting thing I noted was how a few players took the same paths, but used the different weapons and environments to play their own way, and defeat the enemies drastically different from the last person to achieve the same goal. Some players chose to use the different arrows to bomb the camps, some used stealth and assassinated lone enemies (yes, that's a thing), others chose to run into enemy camps swords swinging. The combat system caters to different players' play-styles, and doesn't demand you defeat the enemy a certain way.
Another thing I like is how Link is truly in the wilderness in this game. It was stated that there will be many towns with NPCs throughout this Hyrule, but once Link leaves said towns; Hearts are nowhere to be found in this game. It's up to him to survive using the various resources found throughout Hyrule, keep himself fed, make camp fires to cook meals and elixirs for himself to continue on, and even prepare for bad weather should it arrive (rainstorms douse out camp fires, and may even change terrain). Suddenly, that pot lid shield that the enemy dropped, or that quiver of arrows you found in that chest isn't so useless anymore, because Link's weapons and shields will break after heavy use. Of course, it can be assumed that as Link progresses, he will eventually get a version of the Hylian Shield, and the Master Sword which I highly doubt will break, but until then, the player needs to plan before doing things. Link can either explore a snowy area by carrying a lit torch, eating a spicy dish that he cooked, or wear a warm coat to battle to cold.
I love where the Sheikah (will we finally get to know these people more?) skills are going, some of them look insanely fun to use.
Honestly, if they do half a good a job with the NPCs, town interaction and quests (I would think there will be some, given how enemies drop unique spoils and there are numerous resources in every region) as they did with the wilderness, we might be getting the best Zelda game yet in my opinion. I'd personally love to see the townsfolk interact with you the way they did in Majora's Mask, where they had lives, deep personalities and daily routines that you had to watch out for (examples being Kafei, the Postman's morning runs, certain shops opening up / different people coming out at night, etc).