Meh. This is not a superhero movie, in more than one sense of the word. As far as the genre goes, it's more of a space opera adventure than the normal superhero setting and story. Superman is in it, but he doesn't do anything other than talk to the lead in flashbacks and video calls. And it's a superhero film, because that requires a superhero character, and there is absolutely nothing heroic about the protagonist. She's just an asshole who was handed massive powers, and utterly and absolutely refuses to do any good with them. Also, she's pretty incompetent. She frequently fails in ways she absolutely should not, and also is inflicted with incompetent writing, leading to a great many questions that begin with "Why doesn't she just..."

So Kara, played by Milly "Young Rhaenyra" Alcock, is introduced in the midst of an extended bender celebrating her 23rd birthday. She is apparently traveling around in a small spaceship (where from? Don't know) to planets with red suns, which neutralize her Super powers, rendering her ordinary, like Jor-El and Zod were on Krypton. This allows her to become intoxicated, and she will then cure her hangovers by nipping off to a yellow sun's system where she regains her powers, and is instantly healed. Then she goes back to a red sun and does it all over again. Despite going to a bunch of different planets, they all kind of look the same, with the grungy advanced tech type look, occasionally swapped out for urban squalor or bizarrely primitive aesthetics. Anyway, there is a family living alone in what seems like a farmhouse in the middle of nowhere, and the father/husband is a famous swordsmith. And the villain, Krem, shows up in a spaceship to steal the swords he makes. Because when you have a space ship, you need want? swords, I guess. Bad things happen, leaving a little human-looking girl named Ruthy alone with a single blade from her father's inventory (that appears sized for a small girl), and she sets out on a quest for vengeance, which she pursues by wandering into dive bars announcing her parentage and requesting help seeking "the brigand Krem" in exchange for which she offers the sword once she has used it to kill Krem. People want a sword made by her father, but not enough to guide her on a hunt for Krem, but Kara intervenes when one individual realizes that he doesn't necessarily do what a pre-teen child wants to obtain the valuable object in her possession. Ruthy then latches onto Kara as her potential vengeance helper, but Kara refuses, until Krem wanders by, sees her ship, steals her ship and incidentally poisons her dog, Krypto, with a crossbow, before flying away. FWIW, Krem carries an axe, rather than the inventory of swords he supposedly stole from Ruthy's parents. The tent-dwelling alien apothecary (no, hear me out. This is a sci-fi space movie, I swear) is unable to treat Krypto, but the type of poison killing him is often used by brigands to torture people, so they often carry the antidote on their persons.

So Kara has to employ mass transportation to pursue Krem before her dog's three-day life prognosis runs out. Why she does not just carry Krypto with her to a yellow solar system where he will be instantly cured, is never explained. Anyway, she keeps running into obstacles and bad guys, and Ruthy displays an uncanny ability to follow Kara absolutely anywhere, simply by stowing away, raising the question of just why she feels she needs an adult guide to get her places.

It's a surprisingly uneventful trip, despite efforts to have danger and stuff, and extremely tedious for someone who is supposed to be "Superman, but a cute blonde." For the most part, she just goes around in the oh-so-original costume of a long brown coat, only donning the Supergirl costume for the climactic fight at the end. Frankly, it's more like "Starlord, but a cute blonde." And rather than a supporting cast of entertaining aliens, played by American actors, it's a side-kick and some background humans, played by foreigners, who are not made to speak properly like Alcock does. There are also timeouts to flash back to Kara's origin. It's weird and very very implausible, involving a Kryptonian city floating in space in a forcefield, which, to the utter shock and dismay of the scientists who set it up, begins to have food supply problems over a decade later, so an adolescent/new adult Kara was wrapped in tin foil and put in a big sphere with her pet puppy, and shot to Earth, to join Kal-el (incidentally, there is a line implying Kara's parents disapprove of Jor-El's controversial intentions for Kal's Earth career, but they are sending her to join him anyway). There was potential material there, and you could see a way for this origin to connect with Kara's repellant behavior and petulance, but the film never does the legwork, and does absolutely nothing to support what is close to her character's thesis line, where she compares herself to Clark, saying that he sees the good in people and she sees the truth. There is not one single second of footage of this iteration of Kara before this line is uttered that would inform her more cynical worldview or disenchantment with people in general. The line certainly has nothing to do with her behavior toward Ruthy, and she never evinces any suspicion or cynicism about people's motives. In fact, she's remarkably accepting and trusting of other people, and does not remotely demonstrate any ability or power to detect or anticipate selfish or bad behavior. It's like the whole line is just a random non-sequitur inserted into the film to shit on Clark. And when you consider that the opening scene features Krypto urinating on his picture, it's not hard to leap to that conclusion.

Speaking of Clark, I stand by my contention from the latest Superman movie that this version is not portrayed well. He continues his socially-inept behavior when meeting Kara upon her arrival on Earth, insisting on talking to her in English for the benefit of the audience despite her inability to understand it and giving her a girly version of his costume, stating that it tells people they are good. So Clark is still retarded.

Anyway, another element of note in the film is the introduction of Jason Momoa playing Jason Momoa, dressed as a goth biker who was rejected from KISS for being a little too dull. People call him Lobo, and I suppose he is a comic book character, but his appearances in the movie are rather pointless, and they certainly don't establish any character for him. He's a gruff tough guy, kind of like Wolverine in the very first X-men movie. Actually, a lot like Logan, come to think of it, just without the very specific powers and signature costume & weaponry. Including having a slightly more positive relationship with the youngest prominent female character than anyone else. But all he really does is add to the moving parts of a couple of fight scenes.

Back to the eponymous lead, she has absolutely no arc or journey. She just arbitrarily decides that Ruthy is her friend near the end, a development built on nothing more than "almost a whole movie has passed since they met". It's implied that she has made a major decision to change her life at the end, but it does not grow naturally from anything we have seen her do or experience. It's also hard to care much about her action scenes, because she's potentially so powerful that you can't see how she is in real danger, even in red solar systems, where she is all badass at hand-to-hand combat (with no explanation for any such training, and no real point in her personal time when she could have. She is living a civilian life on her Krypton remnant until she is old enough to be played by Alcock, arrived at Earth where she initially had to cope with suddenly being overwhelmed by superhuman senses, and become colloquially fluent in English as an adult, all well before her 23rd birthday). And of course, her behavior is consistently repellent in ways the movie seems to think are funny, from living on a complete pigsty of a spaceship where a dog pees at will, to eating and drinking random alien crap (literally, at least once) to sharing a spoon with her obnoxious dog. There is not feeling compelled to unrealistic aesthetic expectations and female standards of behavior, and not being actively disgusting, so that you feel uncomfortable on her behalf when seeing her lifestyle. Kara falling into the former category is just fine. There is no ideological/feminist/gender-politics reason accept or excuse her being firmly into the latter.

This is a pointless movie. There is not much of a story, not much of any characters, and it's like a duller, less diverse, extremely lower-stakes version of Guardians of the Galaxy.