'Marines Return' makes extensive use of Ostinatos, played by the short strings. Made popular by the music of Hans Zimmer, an Ostinato is a repeating rhythmic figure used to add drive and propulsion to a piece.
The beginning of the track features a simple 4 note sixteenth note based pattern playing over the chord of Am:
From bar 11 onwards, the ostinato figures follow the harmonic changes. Here you can see that for every four notes, three belong to the relevant chord:
During the B section, the ostinato figure changes shape. This pattern is frequently used in trailer and other action music: