Massive Chinese internet and investment company Tencent has restricted daily the time children and young adults can play its mobile hit Honor of Kings amid fears young people are addicted to the game.

MOBA Honor of Kings is the biggest mobile game in the world. It has more than 200m total users, and 80 million daily active users – most of whom live in China. At any moment, one out of every 17 Chinese persons is playing it, and it was the most downloaded app in the world on the App Store in the first quarter of this year.

However, the game has been criticised by parents and teachers as too addictive, and China's Communist Party news site People's Daily recently described it as a "drug" and "poison", which resulted in Tencent's stock plummeting 5.1 per cent, wiping out nearly HK$136 billion (US$17.5 billion) in market value.

Now, as reported by the South China Morning Post (via Eurogamer), Tencent restricts those under 12 years old to an hour of pre-9pm Honor of Kings gameplay per day. Players between 12 and 18 years old can play for two hours a day, at any time of the day.

Tencent is also intending to add stronger age verification to the game in a bid to assuage fears (and likely to dodge possible government intervention as well).

"There are no rules to prevent indulgence in online games in China, but we decided to be the first to try to dispel parental worries by limiting play time and forcing children to log off," Tencent said.

There is precedent for such restrictions: in 2011, South Korea enacted a law to stop children under 16 from playing online games between midnight and 6am.

In 2014, Vietnamese developer Dong Nguyen pulled mobile sensation Flappy Bird from App Store despite its US$50k daily revenues, because he felt it was too addictive.

"I think it has become a problem," he said at the time. "To solve that problem, it’s best to take down Flappy Bird. It’s gone forever.”

At that time, an average of 60 Flappy Bird clones were hitting the App Store every day.

The game then surfaced six months later in the Amazon Appstore.

Tencent is the second-largest company in Asia. It owns a majority stake in League of Legends developer Riot Games, among others.