Puskin's novel is important because it was a radical break away from the densely descriptive, flowery prose of his predecessors.  Like Hemingway would do a century later, Puskin opted for sparse detail to tell the story of his troubled protagonist, Hermann. 

Puskin also changed course in literary style by using omniscient narration, a break from the earlier style of first person narration.   Pushkin's use of symbolism also engaged and inspired other writers of the mid-to-late 1800s.  The Queen of Spades, while not widely read today, is nonetheless cited as one of the primary influences on Russian literary style.