The Three-Body Problem has been the most popular radio play on Ximalaya, says Jiang Feng, vice-president of the online platform. The most common comments on the app are "too short" and "new episodes released too slow".

"On average, we can produce one episode in one to two weeks. If we increase the length to one hour, the production cycle will have to double," says Zi Tangxiu, CEO of 729 Voice Studio.

Despite its popularity around the world, The Three-Body Problem trilogy would be difficult, with its imaginative plot, to adapt for screens. Comparatively, radio presents the story with just voices and can avoid these difficulties, says Cheng Han, scriptwriter of the radio play.

However, it does not mean that the radio play adaptation is easy. It took Cheng three months to write the first episode.

"I was not satisfied with my work, so I kept starting over, again and again," says Cheng. As a fan of Liu and the trilogy, Cheng says she felt a pressure to do her best.