Chinese gaming firms including Tencent and NetEase have been summoned by the Chinese government to ensure new rules regarding limiting gaming time for minors are being implemented.
In late August new regulations were announced that limit under-18s to just an hour of gaming per day - between 8pm and 9pm - and only on Fridays, Saturdays and Sundays.
The restrictions apply to any devices capable of gaming, including phones.
That follows an earlier crackdown, announced in July by Tencent, where it started using facial recognition technology to stop children playing games between 10pm and 8am.
But that clearly wasn't enough for the government, and companies that are found to have "inadequately" implemented the regulations will be severely punished.
The state-run Xinhua News Agency reported the Communist Party's Publicity Department, the National Press and Publication Administration, the Office of the Central Cyberspace Affairs Commission and the Ministry of Culture and Tourism called the meeting to inform the companies about plans to increase supervision and start checking on illegal behaviour.
The companies were also ordered to remove obscene and violent content and avoid "unhealthy tendencies, such as money-worship and effeminacy".
The tightening of rules on gaming comes as part of a call for a "national rejuvenation" from President Xi Jinping. That means tighter Communist Party control on religion, education, culture and business.
Didi, an Uber-like ride-hailing service, and popular social media accounts have also been targeted by those in charge.
The Cyberspace Administration of China has shut down and banned 1793 so-called self-media accounts on online platforms in the last two weeks, Reuters reported.
That included three with more than a million followers and more than 47,000 pieces of "harmful information" being deleted.
The Washington Post reported social media platforms like Weibo have also banned real-time popularity rankings of celebrities and suspended fan club accounts.