Young circus ringmaster Wei Wei has only bat-swinging gorilla Ling Ling to depend on as her only family member and friend, when her grandfather dies in the Great Sichuan earthquake, leaving behind an insurmountable debt. When a loan shark threatens to sell Ling Ling and the circus kids to cover the debt, Wei Wei has no choice but to allow Ling Ling to be scouted in the Korean Baseball League by the materialistic sports agent Sung. Ling Ling, now dubbed "Mr. Go," becomes an instant hit with fans and leads his team Doosan Bears to a miraculous winning streak.
Kim Yong-hwa, director of box-office hits 200 Pounds Beauty (2006) and Take Off (2009), decided to adapt Huh Young-man's 28-year-old comic after seeing the YouTube video of Christian the lion, which demonstrated that humans are capable of taming animals. But for the film to work, the gorilla had to look like a living creature. Kim decided to shoot entirely in 3D, and of the 2,000 shots in the film, 1,000 are special effects shots of the gorilla Ling Ling. For four years, a team of more than 500 animators and CG professionals led by visual effects director Jeong Seong-jin developed motion capture technology, facial motion capture technology and a digital fur production program to make the gorilla as realistic as possible, followed by another year of editing. The images were so precise and delicate that all the 3.8 million hairs on Ling Ling could sway with the wind.
With consultant Kim Tae-yong of Rhythm and Hues Studios (famous for its work on Life of Pi), the production team established a new company Dexter Studios (with 180 employees), which created the software Zelos System to process large amounts of data efficiently so that the film cost 10 percent of the budget demanded by most Hollywood movies. The budget was ₩20 billion (or US$18.62 million), with ₩12 billion spent on visual effects. 25% of the budget (or US$5 million) came from Chinese investor Huayi Brothers. It also received ₩30 million from the International Co-Production Incentive Support 2013, a project run by the Korean Film Council (KOFIC), and director Kim spent ₩3 billion from his own pocket.
The movie's theme song "Bye" was sung by Kim Tae-yeon, a member of Girls' Generation. Composed by music director Lee Jae-hak, "Bye" had a Korean version and a Chinese version. The score was recorded by the Hollywood Symphony Orchestra at Sony Pictures' Scoring Stage in Los Angeles, CA.
The film opened on 1,000 screens in South Korea on July 17, 2013, and on 5,000 screens (all in 3D) in China on July 18. It was also released in other Asian countries, namely Singapore on July 25, Malaysia and Thailand on August 1, Indonesia on August 6, Taiwan on August 9, Hong Kong on August 15, and the Philippines on October 16.
Due to competition with other summer blockbusters such as The Wolverine, Snowpiercer and The Terror Live, Mr. Go had a disappointing box-office performance on its opening weekend in South Korea, drawing 540,411 moviegoers at 788 screens. It grossed a total of ₩9,311,311,000 (US$8.65 million) domestically on 1,325,039 tickets sold.
In China, the film topped the box office on its opening day, earning CN¥12.2 million, which is the highest single-day record for a Korean film in the country. It grossed a total of CN¥112.73 million (US$18.12 million) in China.