The Legend of Zelda: Tears of The Kingdom was an amazing game from sart to finish. It wasn't a perfect game, because there were some flaws, so I would personally rate it 9/10. Some people say that it is just a DLC to BotW, but for me, it is more then just that. There is a bigger world, including the sky islands, the ground (Hyrule) and the depths. I would like to give a spoiler warning here, as I will be talking about the story.
You start off on the Great Sky Island, which is basically a tutorial. After you complete three shrines, you go to the temple of time. Then, you need to go back to another shrine, complete it, and open the back door to the temple.
You then go to lookout landing, and activate the skyview tower. You then go back to Paya and learn about phenomeneas happening in every region. It is like BotW, but is better because instead of divine beasts, they brought back dungeons. After you beat all four dungeons, theres a fith that you can beat.
Then, you will face offf against Phantom Ganon. After you beat him, you will go to the depths to fsce off against the Demon King's army, which are basic enemies affected by gloom. Gloom is a substance found in Hyrule (mostly in the depths) that if you stand on it too long (or get hit by a gloom enemy) then you will temporarily lose a heart (you can't regenerate it back). To get a heart back, you can just go find a lightroot or something like that. You can also eat gloom resitant food.
After you face the Demon King's army, you face off against the Demon King himself, Ganondorf. Be mindful that a lot of your normal attacks are ineffective here, because he can dodge some of your attacks. The most effective attack you can use on this boss fight is flurry rush. After you beat him, he has a second phase, where he spawns 4 more of himself and has doubled his health. If you manage to beat that, he goes to his final phase, Demon Dragon. Don't stay on him for too long, because he is made up of gloom. If you manage to beat Demon Dragon, you beat the game!
Overall, this game is a near-perfect sequel to BotW