My wife and I left about 80 minutes into the movie. The first 10 minutes shows a pair of soldiers trying to get off the beach on to a boat to England by any way possible, fair or foul. It shows planes flying in formation, breaking off formation, a pilot's eye view of a hard turn, a close up of the pilot, and some gunfire from a plane. It shows the goings-on aboard a small civilian boat heading to Dunkirk to rescue trapped soldiers. It shows a military boat sinking from a bomb or a torpedo, men jumping overboard, and others struggling not to drown. The next ten minutes shows the same thing, as does the next ten minutes, the ten minutes after that, and ... you get the idea. After about our fourth round of "we've seen this already, and this is going nowhere", we left. The "trapped underwater" scenes are very disturbing even if deaths are avoided or not shown.

The beach, sea and aerial scenes are on different timelines that I assume converge at the end, but it can be very disorienting to jump from day to night and back again between scenes not knowing where the three timelines are relative to one another. There were a few instances of coming into a scene knowing exactly what was about to happen because you had already seen it on another timeline.

I've seen 60-second commercials with more dialog and character development than this movie had 80 minutes in. What a waste of time and money.