Well, let's start with the narration of this excellent tale. Like many of Poe's classic short stories, this tale uses an unreliable narrator to tell us what is going on. He is clearly unreliable through the way that he admits he struggles with drink and how he acknowledges what a powerful hold alcohol has on his life, and how he refers to the impact of the "instrumentality of the Fiend Intemperance" and how this turns him into a desperate, violent individual.
Another literary element is clearly the use of the supernatural, and in particular the way that Pluto is apparently resurrected after being hung, and how Pluto gets his revenge through revealing to the police the location of the body of the narrator's wife.
There is a sense in which this tale too is more than a simple account of a drunken man. Parts of this tale fit into the psychological thriller category, as Poe unfolds to us the thoughts of a killer and explores how he descended to this state and what it led him to do.
Lastly, you might wish to think about the kind of language that is used by the narrator to describe his increasing loss of control and the way that anger rules him. For example, note how he narrates the murder of his wife:
Goaded, by the interference, into a rage more than demoniacal, I withdrew my arm from her grasp and buried the axe in her brain.
The use of the word "demoniacal" seems to indicate that there is something supernatural or not quite right about the man's rage, and also could be an effort by him to deny responsibility and blame alcohol for making him do what he did.