Dunkirk is an unusual World War 2 film that manages to be quite absorbing, though its approach might not appeal to everyone. Often, when discussing a movie, people focus on what it's about—the subject matter—but really it’s the characters who drive the story. Saving Private Ryan isn’t truly about World War 2; it centers on a group of soldiers trying to locate and safely return a young soldier to his family. Describing Dunkirk as a film depicting the Battle of Dunkirk isn't entirely wrong, because in this case, the setting and the characters are intertwined. The turbulent waters of the English Channel carry just as much weight, if not more, than those who perished or fought there. While this represents an intriguing method for crafting a mainstream war movie, it’s also why I don’t feel compelled to rewatch it. Parts of it felt like experiencing a documentary without any voiceover explanation. I left the theater feeling impressed, yet somehow emotionally and mentally wanting more.

Source on TMDB