Supergirl opens with a version of Kara Zor-El who has already grown tired of being compared with her cousin.
Superman landed on Earth as an infant and grew up believing the world was basically worth saving. Kara remembers Krypton. She remembers the people who died there, the life she was supposed to have, and the years spent traveling toward a planet where someone else had already become the symbol of her family. The difference is not a footnote. It is the entire performance Milly Alcock builds.
Her Kara drinks too much, fights too quickly, and treats heroism as a responsibility she would rather deny than fail. Alcock does not play the rebellion as a collection of poses. Her sarcasm has fatigue underneath it, and her anger often arrives half a second before fear. Even when the screenplay gives her a familiar superhero line, she finds a way to make it sound like something Kara has said to keep people from asking a harder question.
The film draws heavily from Tom King and Bilquis Evely's Supergirl: Woman of Tomorrow, pairing Kara with Ruthye Marye Knoll, a young girl seeking revenge against Krem of the Yellow Hills. Eve Ridley gives Ruthye a seriousness that prevents her from becoming the child sidekick who exists only to soften the hero. She is angry, exacting, and often more committed to the mission than Kara is. Their relationship works because neither character is especially interested in being improved by the other.
Craig Gillespie understands the appeal of that pairing. His best scenes allow Kara and Ruthye to sit inside their conflicting ideas of justice. Ruthye believes vengeance will restore order to a world that failed her family. Kara knows enough about loss to recognize the lie, but not enough about herself to explain it without sounding like a hypocrite. Alcock and Ridley make those conversations more complicated than the film around them.
The problem is that Supergirl repeatedly leaves this emotional conflict for a more routine interstellar chase. Krem, played by Matthias Schoenaerts, is cruel enough to move the story but rarely specific enough to haunt it. Schoenaerts gives him a cold, controlled presence, yet the adaptation strips away much of the moral and political texture that made the comic's journey feel so unusual. He becomes another villain waiting at the end of another route across the galaxy.
Alcock plays Kara as someone who can survive almost anything except being asked to explain why she is still angry.
The movie also gives Krypto a central role. The dog remains an easy source of affection, but his presence is not merely comic relief. Krypto connects Kara to Superman and to a gentler kind of responsibility she is reluctant to acknowledge. A plot turn involving his safety pushes Kara and Ruthye deeper into the pursuit of Krem, although the digital animal is not always convincing enough to carry the emotional weight placed on him.
Jason Momoa appears as Lobo, a casting choice so obvious that the film sometimes seems satisfied simply to have completed it. Momoa has the physicality, swagger, and appetite for chaos the character requires. He is funny in short bursts and brings welcome disorder to the middle of the film. He is also only loosely connected to Kara's emotional journey, and his scenes often feel imported from the larger DC Universe rather than grown from this story.
That larger universe is mostly kept at the edges. David Corenswet's Superman is present without taking over the film, which is important. Supergirl works whenever it resists defining Kara through him. The contrast between them matters, but Alcock's performance does not need to borrow significance from another hero. Kara's grief, temper, and refusal to behave correctly are enough.
Rob Hardy's cinematography gives the planets varied surfaces and lighting, but the film's visual imagination rarely matches the singular beauty of Evely's artwork. The comic created worlds that looked hand-built from color, architecture, and impossible skies. The movie often settles for competent digital space environments. They are large without being memorable.
Gillespie brings more personality to the smaller moments. A bar, a cramped vessel, or a conversation held after the adrenaline has faded gives Alcock room to make Kara feel unguarded. The action is less distinctive. Several fights are clearly staged and easy to follow, but they arrive with the familiar rhythm of impact, recovery, and escalation. For a hero whose relationship to violence is central to the story, the violence itself feels surprisingly anonymous.
Claudia Sarne's score pushes against that sameness with rougher textures and heavier percussion than the bright orchestral language associated with Superman. It gives Kara's movement a sense of resistance. She does not glide through space as though flight were freedom. She often looks like someone forcing herself forward.
The screenplay's strongest idea is that Kara and Ruthye are both using revenge to postpone grief. Its weakest habit is saying that idea more plainly than the characters need. Ana Nogueira gives Alcock several sharp exchanges, but the film sometimes turns emotional subtext into instruction. The actors are capable of carrying more silence than the movie allows them.
Supergirl is not the disaster suggested by its worst moments, and it is not the bold reinvention promised by its source material. It is a functional space adventure built around an excellent lead performance. That imbalance becomes frustrating because Alcock continually shows the better film waiting inside it.
She gives the DC Universe a hero who is messy without being cynical, wounded without becoming humorless, and powerful without finding power especially comforting. By the end, Kara has not been polished into another symbol. She remains difficult. The film should have trusted that difficulty more often.
