There are probably many reasons why people dislike it but I think that one of the main reasons are that they have no idea what happened before the new ousama game. In the anime they have flashbacks of what happened in the "old" ousama game. The flashbacks are scenes from the manga so that people who haven't read the manga could understand the anime.
----spoilers----
So in the end of the manga you get to know who the ousama is and what it does. So I'll explain what the ousama is. The ousama is practically a "virus" looking for a master. It looks for it's master by making a game on whoever finds out the truth about ousama will be able to control ousama and use it as a weapon to conquer the world. That's just a brief explanation of what the ousama is so I'd suggest you to read the manga to understand. But when Nobuaki won the game, the ousama messaged him "what's your order, master" and then the manga ends.
And that's why I'm so confused of why there's a new ousama game. Nobuaki not only won the game. He became the master of the game. So why would the game continue? The manga also explains how the ousama game started and works and knowing that the anime makes a lot more sense.
