Tom King and Bilquis Evely’s 2021–2022 miniseries Supergirl: Woman of Tomorrow, the primary inspiration for DC Studios’ Supergirl, was a sci-fi True Grit story. It provided a unique outsider perspective toward the Girl of Steel as she helps a young girl track down her father’s killer, analyzing not only the nature of vengeance in a harsh galaxy but also the coping with the trauma of loss. For Kara Zor-El, that means grappling with being the only Kryptonian survivor with memories of Krypton before it exploded, a luxury not even her famous cousin Superman possesses.

Supergirl is at its best when delving into how Kara processes her trauma outside the bottom of a bottle, with Milly Alcock rising to the task following her unexpectedly inebriated Superman cameo. It’s a shame the rest of her movie doesn’t quite match that quality, delivering a competent but uneven planet-hopping adventure that only scratches the surface of what its hero represents to the galaxy at large.

Unlike Superman, which introduced David Corenswet’s Boy Scout alongside an entire planetary super-status quo, Supergirl’s adventure is largely a standalone saga. Superman does make a few cameos checking in on Kara’s well-being and asking when she’ll return to Earth, but she’d prefer to party. Celebrating her 23rd birthday by pub crawling the cosmos in a spaceship with a mobile home interior, Kara’s activities consist of visiting clubs, drinking her troubles away, and waking up with massive hangovers—albeit with a few small but sentimental moments of playtime with her rapscallion super-dog, Krypto. During one bender, Kara finds her evening interrupted by a young girl, Ruthye (Eve Ridley), who seeks to hire a patron at the bar to shed blood on her behalf. A brute named Krem of the Yellow Hills (Matthias Schoenaerts) killed Ruthye’s entire family and, armed with her father’s sword, Ruthye will go to any length to ensure Krem and his raiders pay the price.

However intoxicated and reckless she may be, Kara still has morals, warning Ruthye against pursuing futile vengeance quests. Then Krem makes things personal, stealing Kara’s spaceship and shooting Krypto with a poisonous arrow that will kill him in three days unless she recovers the antidote hanging around Krem’s neck. Forced to travel across the galaxy with Ruthye in tow, Supergirl battles pirates, cutthroats, criminals, and an inner rage that comes from enduring all she’s lost. And that’s all before the ruthless, crude, and all-around destructive bounty hunter Lobo (Jason Momoa) shows up, hunting down Krem’s crew for money but happy to blow shit up along the way.

Tonally, Supergirl isn’t quite trying to replicate James Gunn’s Guardians of the Galaxy space adventure vibe, despite featuring plenty of aliens and needle drops. Instead, director Craig Gillespie (I, Tonya) makes Kara’s world feel grungy and unkept, populated by Mad Max–inspired lawbreakers who enjoy sparking chaos for extraterrestrial citizens going about their lives. Some scenes are loosely adapted from Woman of Tomorrow, such as Kara witnessing the deterioration of Krypton’s refugee colony, Argo City. But Supergirl never gives these worlds and creatures much personality beyond appearances, making Kara and Ruthye’s encounters with them feel more like set dressing than a fully realized universe.

It also takes a while for our lead duo’s relationship to get going, with Kara primarily rescuing Ruthye from danger and the latter only sporadically getting the chance to protect Supergirl in turn. Having an underwhelming villain doesn’t help matters either. Krem always comes across more like a plot device than a fleshed-out antagonist, despite Schoenaerts doing his best to ham up the fiend’s unrepentant villainy. By comparison, whenever Supergirl or Ruthye partner up with Lobo, things become delightfully crazy. Though he’s not on screen much, the former Aquaman star was born to play the Main Man in all his ruthless, darkly hilarious glory. From Lobo’s psychopathic cigar-chomping to his look of pure glee when smashing a metal hook and chain into heads, Momoa is having an absolute blast in this role, and one hopes he returns for more chaotic DC team-ups.

It’s Alcock’s performance that helps stitch Supergirl’s underdeveloped ends into something reasonably engaging. Unlike her idealistic Arrowverse TV counterpart played by Melissa Benoist, this Kara understands how to be a hero yet struggles with the emotional baggage of never forgetting all she’s lost. This heartache creates a jaded detachment she must work to overcome, resulting in that big, inspiring moment when she finally dons the big red S. As Ruthye puts it so frankly, “You’re not always nice, but you are kind.” Even when Supergirl is flying, punching foes at super-speed, or casually intimidating them with heat vision, that mantra seems to hold true.

Supergirl is rough around the edges, especially when the movie tries to give its worldbuilding some added intrigue or dimension. Nevertheless, the hero at the heart of this story is still worth rooting for, even if the complete package never quite reaches “super” status.