This movie is a nationalistic propaganda loved by China, because it is about Taiwan.
The island of Taiwan was taken by Dutch, taking advantage of the corrupted and collapsing Ming Dynasty, which soon collapsed under Manchu attack. The protagonist, Cheng-Gong Zheng, a loyal subject of Ming Dynasty wanted to use Taiwan as base to restore the Ming dynasty in China, so he fought with Dutch and took back Taiwan, and since the 2000 presidential election of Taiwan resulted in putting the pro-independent candidates into presidential office, this propaganda served China well in advocating the unification of Taiwan, and that's why Chinese government had its full support to Hong Kongers who made this movie.
The island of Taiwan was taken by Dutch, taking advantage of the corrupted and collapsing Ming Dynasty, which soon collapsed under Manchu attack. The protagonist, Cheng-Gong Zheng, a loyal subject of Ming Dynasty wanted to use Taiwan as base to restore the Ming dynasty in China, so he fought with Dutch and took back Taiwan, and since the 2000 presidential election of Taiwan resulted in putting the pro-independent candidates into presidential office, this propaganda served China well in advocating the unification of Taiwan, and that's why Chinese government had its full support to Hong Kongers who made this movie.