Kuo Sin's work ranges from documentaries and variety shows to dramas and comedies. In 2012, he released his first feature film, Judgment Day / 世界末日, which went on to earn RM1.5 million in Malaysia. In 2014, Kuo Sin earned a nomination for "Best Local Director" in the Singapore E-Awards. In 2015, he wrote and shot the viral hit song "Unbelievable" for Spouse For House, which garnered more than 5 million hits online. He also wrote and shot the feature film Mr. Unbelievable, inspired by the "Unbelievable" MV.