I'm not being objective...
I've just finished Outer Wilds and the only thing I want to do is forget about it and start again. Above all, I just want to share it.
Play Outer Wilds!
Play it, not necessarily today or even this year, take the time to get yourself in the right conditions, play it when you feel ready.
But play it!
It's a unique experience, and you won't regret the trip. Don't spoil anything for yourself, make the most of every moment - once you've reached the end, you'll wish you'd taken more time. No other game has made me feel so alone and so insignificant. Yet I came away with a unique and indescribable feeling. I'll end this review with:
PLAY OUTER WILD!

So why is Zelda: BOTW the best game in the world?
Before we start talking about the game itself, let's try and define what video games are in general. I don't need you to agree with me, but games are first and foremost an art form, or at least a medium based on interaction. It's our decisions and our involvement in the story that has advanced it.
Zelda BOTW is the best that video games have to offer in terms of freedom and interaction with the world. There's nothing to limit your progress - you can make just about any decision you like, and you'll always come out on top. If you want to cross a chasm, cut down a tree to build a bridge, climb to the top of a hill to use your paravane, light a campfire so you can use your paravane to climb up, or simply walk around. I've taken a simple example of a chasm, but it applies to all the gameplay, as well as to the story as a whole.
I've never felt so free as when I was wandering around Hyrule, trying to decide whether I'd rather go to the mountains to the north (where the Gorons live) or head for the hills of the Zorra domain.
Explore, test, try again, and have fun - that's what Zelda BOTW is all about.