Besides the technical difficulties, the pair has burned the midnight oil on many nights to study related theories, reading papers on mathematics, physics, chemistry and astronomy from home and abroad to gain theoretical support.

It took the team one week to finalize the size and thickness of the Dyson Sphere's crust and energy-absorbing efficiency through repeated data checks, calculations and modeling.

"Making a game like this is not easy. We need to cater to those hardcore sci-fi players who know every subject and have high demands. That's why we've been studying — even quantum mechanics," Li said.

The team has been patching a lot, too, fixing bugs and addressing concerns raised by players, to ensure there are no big bugs that impede game play.

The concept of the Dyson Sphere was originally proposed by British science fiction writer Olaf Stapledon in his novel Star Maker in 1937. It was popularized by British-American theoretical physicist and mathematician Freeman Dyson in a paper talking in 1960 about the concept of a giant spherical solar power station. The spherical structure was often mentioned by engineers and sci-fi writers and later became known as the Dyson Sphere.

With practical scientific significance, the concept might solve the energy crisis on Earth, as well as support humans in interstellar exploration and extraterrestrial emigration. DSP takes players to that distant future — as does another great Chinese work of science fiction, The Three-Body Problem — and triggered a surge of interest among Chinese animation fans and sci-fi aficionados.

"The process of building a Dyson Sphere is quite similar to human civilization. It's going to be hard work, but we'll win through in the end," Li said. "Human beings have been very curious about the universe, hoping to unveil its mysteries one day. And our courage to explore is expressed in science fiction. After all, science fiction is a kind of romance for all mankind."