China steps up oversight
The first reaction of most people is going to be that China is acting like a Communist country and way overstepping its boundaries. There's undoubtedly some truth in that.
At the same time, China has legitimate worries that video games are causing addiction and a sedentary lifestyle.
Globally, every society is going to have to deal with video games because the makers have gotten remarkably good at making them addictive. Combine in the constant accessibility of mobile games and you get real problems.
As for the details, regulators had left open a 'green channel' for approving games after reviewing them for violence, gambling and other sensitive topics but that has now been stopped.
The news isn't helping Tencent, which is down 1% on the news. The company has lost $156 billion in market cap this year.
Here's an article that really opened my eyes to what's happening with kids and the video game industry: https://www.businessinsider.com.au/heres-what-defenders-of-fortnite-refuse-to-accept-and-its-ruining-an-industry-thats-supposed-to-be-fun-2018-9