There is musical term known as staccato. The definition is "marked by short clear-cut playing or singing of tones or chords." The musician accents short and simple notes, allowing silence in between. The music does not flow, but "drums" along, note by note.
Hemingway's writing is often staccato. Look at this passage from "Old Man":
They sailed well and the old man soaked his hands in the salt water and tried to keep his head clear. There were high cumulus clouds and enough cirrus above them so that the old man knew the breeze would last all night. The old man looked at the fish constantly to make sure it was true. It was an hour before the first shark hit him.
This is a paragraph of simple sentences. But the purpose of these sentences are not just to provide simplicity, but to create flow. The staccato sense adds to the mood of the novel, the sense of time hammering away at the old man as he tries each passing day to succeed. The pace is stilted, harsh. There is little sense of being "swept along" by the language. Instead, the language - like the conflict - requires constant, repeated, attention.
For a last note, see how different the pace seems if we combine the first two sentences:
They sailed well, the old man soaking his hands in the salt water, trying to keep his head clear while the high cumulus and cirrus clouds looming above let the old man know the breeze would last all night.