Is this story a tragedy or a comedy? Is Mitty simply a daydreamer, or is he suffering from a more serious condition?

Here are a few analytical points about the story that may help you in writing this assignment.
Walter Mitty is a man whose normal everyday life leaves him feeling insecure, powerless, and lacking in masculinity, heroism, and independence. His wife seems to order him around, and he either begrudgingly obeys her or pretends to follow her orders and rebels when she is not around. His everyday life and the things he sees in the story prompt him to have fantasies or daydreams. These daydreams symbolize the powerful, forceful man he wants desperately to be.
The naval commander symbolizes Mitty's desire to show daring and heroism in the face of danger. The doctor Mitty daydreams himself to be reveals his desire for respect for others and his wish to show his intelligence and resourcefulness. The courtroom scene, in which Mitty proclaims his skill in shooting, again reveals his desire for others to see him as powerful and even potentially dangerous. Mitty's other imagined characters, such as the fighter pilot and a man facing death, reflect the same need for others to see him as courageous, masculine, and strong.
Mitty's wife, oblivious to her husband's need to be seen as someone important and meaningful, reveals her true lack of understanding and her insensitivity to his needs. She exerts her power over him in many ways that make him feel trapped and insignificant.
One possible theme of this story is masculinity and the male ego. Domestic life for this man does not allow him to show the more powerful, courageous side of his nature, a side that has been glorified throughout history. Without this ability, he may feel trapped in a world that will never give him the opportunity to show his true vigor and heroism. Thus, he never feels the satisfaction of growth and self-actualization.
Another theme involves the impact and appearance of fantasy in everyday life. People frequently rely on fantasy to live out parts of themselves that they feel are lacking in real life. These fantasies allow them to escape the drudgery and oppression of their real lives.
More themes to consider are the secrets that people keep from others, such as Mitty's use of the sling to hide his shame at not being able to properly change or remove the tire chains. Oftentimes, people hide their true selves to avoid the harsh judgments of others.
While this story has its humorous moments, it is actually a dark tale about the dissatisfaction that many people experience in domestic life and the secret desires that lie unfulfilled within them.