The Brother from Another Planet, directed by American independent film genius John Sayles, is an iconic science fiction film from 1984 that elegantly blends nuanced humor, social commentary, and poignant drama.

The lead role is handled by Joe Morton, who delivers a brilliant performance as 'The Brother,' also known as 'The Alien.' Morton's character is a mute extra-terrestrial being who can't communicate using human language but projects and feels human empathy—a unique rendering of an alien. He is an unusual visitor from another world who doesn't emit beams from his eyes or rides in a ship, but resembles an African-American man. Everything about his persona is human, but his detached aloofness and mute disposition suggest another reality. His race, quite brilliantly, enunciates the racial themes of the movie.

Playing a close-to-silent character, Morton performs with expressions, physical gestures, and delicate movements to convey his character's thoughts and feelings. It is a testament to his skills as an actor to bring depth, likability, and empathy to such a character; it is an incredible achievement that Morton pulls off.

Daryl Edwards and Rosanna Carter are also part of the cast and deliver stellar performances, each adding depth to the complex storyline. Daryl Edwards takes on a significant role in presenting the social layer of the narrative. His performance effortlessly brings life to the gritty reality of everyday city living, the positives and negatives of community, and the heartwarming warmth found in unexpected places—the central themes of this socially conscious drama.

The plot of The Brother from Another Planet is a socially-relevant narrative that weaves science fiction into the very fabric of urban life. It is the story of an alien who crash-lands in New York City and has to adapt to a world completely different from his.

In his new host environment, The Brother encounters the usual urban realities—drug peddlers, downtrodden victims, chirpy bar-goers, and encountered men hired to capture him and bring him back to his home planet. Here is where John Sayles's masterful storytelling comes in. He doesn't just use these social constructs as mere props, but explores them deeply, making them integral parts of the narrative. They become vehicles to drive home social commentary on race, class, and the human condition.

Set against the backdrop of the Harlem neighborhood in New York City, the film showcases a gritty, authentic setting that truly adds to the film's realism. It is a joyful celebration of local culture and community, adding a distinct human touch to the science-fiction narrative. This contrast of urban life against a subtle science fiction backdrop adds the uniqueness to the film.

If the performances and the plot make up the riveting, moving body of the movie, the thought-provoking social commentary forms its soul. It's a reflection on the human condition, looking at where we come from, who we are, and where we are going, which is quite ironic coming from an alien perspective.

The Brother From Another Planet is a cinematic illustration of how social barriers break when it comes to encountering visitors from a "different world." By putting an alien in place of an African-American man Sayles smartly underlines the ironies of the American society where the color of the skin sometimes determines one's 'alien-ness.' Here, even an alien gets accepted by the society while the locals still grapple with racial disparities.

The movie is an intelligent mix of genre content and social observation that goes beyond mere entertainment to challenge and question, something that only a few films can successfully pull off.

In summary, The Brother from Another Planet, featuring the brilliant Joe Morton, Daryl Edwards, and Rosanna Carter, is much more than a science-fiction comedy. It's a thought-provoking cinematic experience that delves deep into urban life, race, human nature, and the sense of community we share, all from an intergalactic visitor's perspective. For anyone who’s a fan of intelligent and meaningful cinema, this film is an unmissable gem from 1984 that remains relevant even today.