A big swing and a small miss. Supergirl is an almost direct adaptation of Tom King and Bilquis Everly's award-winning, 2021 comic series, Supergirl:Woman of Tomorrow.
Almost.
The premise is roughly this - Supergirl, aka Kara Zor-El is somewhat more relaxed and hedonistic than her cousin, Superman. To celebrate her 23rd birthday, Kara is enjoying an epic bender on a series of planets with red suns - where her powers are naturally weaker and she is therefore able to get drunk. During one bar visit, she becomes involved with Ruthye, a local girl who wants to avenge the death of her family at the hands of Krem of the Yellow Hills.
Krem is a Brigand - a sort of space pirate-cum-viking - who with his fellows travels from world to world sacking, pillaging and generally terrorising anyone in his path. Kara doesn't want to get involved, but Krem makes the mistake of shooting her dog, Krypto (an adorable CGI creation) with a poison dart to which only he carries the antidote, and she is forced to pursue him across space with Ruthye in tow.
The way this plays out in the comic is via a series of encounters on different planets, during which Krem exploits some of Kara's Kryptonian weaknesses, and our heroines face other obstacles, including a seemingly perfect planet with some rather unpleasant secrets.
What we get instead is a sort of fast-forwarded version of the quest, with sadly a lot of the meatier story elements removed. We also get - for no reason I can fathom other than Jason Momoa wanted to play him - Lobo, a near-immortal 'Czarnian' bounty hunter who comic readers will know as an extremely 1990s force of chaos and violence. Momoa is actually pretty good as the Czarnian and clearly born to play the role but otherwise Lobo adds absolutely nothing to the film beyond additional run time.
Contrary to what you may have read in the crapper end of social media, Milly Alcock is terrific as Kara and she completely nails the character. Sadly she just isn't given enough to work with. Eve Ridley makes the most of Ruthye and Matthias Schoenaerts does his best as Krem but again the character is underwritten and more of a plot element than a person.
I cant help but feel DC Universe-supreme leader James Gunn would have made a better hash of this than Craig Gillespie, whose vision of the cosmic side of the DCU feels like a reheated version of Gunn's Guardian's of the Galaxy movies.
This is not to say the film isn't entertaining. It is a solid mid-tier superhero romp. It just could have been much more.