Conjugal relations, the ties of kinship and other kinds of intimacies that prevailed in the pre-catastrophe world are all abandoned. A strict social hierarchy has been created based just on the quality of people's genes. Only the elite have the right to pass their genes on to the next generation as well as hold important positions－such as soldier, researcher and doctor－that allow the place to function well. The masses, at the bottom of the hierarchy, are identified by a number, perform menial, manual tasks and have to live in substandard housing.

A team of well-trained soldiers, called "hunters", has been formed and dispatched to the hazardous post-disaster wasteland, where they have to fight against titanic monsters to search for useful resources for the lighthouse's dwellers to survive.

The combat between humans and monsters and the collision between the upper and lower classes move the plot forward. How Ling Cage unfolds has been a hot topic online.

The animation, updated on the video-sharing platform Bilibili once every two weeks, has notched up 250 million views and attracted more than 4 million danmu, or short live comments, on the platform. It has obtained a rating of 8 points out of 10 on China's popular review platform Douban and been hailed as a production that brings hope to the development of China's animation industry.

Cuchallain Real, a YouTube user in the United States, posted a video to review the animation, saying: "The environments, in particular, are incredibly detailed and give a realistic appearance of many different forms of materials, from the more synthetic metals and plastics, to the natural flora which has emerged from the post-apocalyptic landscape." He adds that the visual effects blend well with the 3D animation.

Ruan, also the animation's producer, points out that to make an animated work based on imagination, the production unit has to deal with each detail with rigor.

"The use of background music and audio effects should help to create an immersive experience for the audience, and a good story should also be thought-provoking," he says.

The value of human unity has been highlighted in the lead-in of each episode which reads: "No matter what kind of difficulties or challenges we have to face, mankind, with a shared future, should dispel prejudices and stay united to sail up the river of time."

Ruan says he hopes that the audience will not just be visually entertained by the high-tech elements, such as battle robots and cool fighting scenes, but will also be able to reflect on their own lives.

He also thinks highly of the prospect of China's animation industry. "For one thing, the video-sharing platforms are willing to give us more decision-making powers and time to create high-quality content," he says. "For the other, the commercialization, such as sales of merchandise, product placement and related game development, has become unprecedentedly clear for us."