When the original Guardians of the Galaxy hit theaters three years ago, I was skeptical. A director as idiosyncratic as James Gunn seemed a strange fit for Marvel at the time, and taking a largely Earth-tethered superhero universe all the way into outer space seemed like a risky proposition. I remember telling a friend that it felt like like a make-or-break moment: Marvel was either going to prove it could expand beyond the well-known heroes that had come before, paving the way for subsequent phases of its cinematic universe, or Guardians of the Galaxy would fall flat.

By the time Chris Pratt finished dancing through Guardians’ opening credits, I was in love, and the first installment turned out to be one of my favorite films the studio has ever produced. Mixing a surprisingly earnest story with its whackadoo space-opera sensibilities, Guardians felt like a rebooted Star Wars before Star Wars had even rebooted itself, and I couldn’t wait to see how the second installment would surprise and delight.

It turns out hitting a home run is really hard.

Gunn knows an audience favorite when he sees one, and he uses the credit sequence of Guardians of the Galaxy Vol. 2 to focus heavily on the most adorable character in his arsenal: Baby Groot (again voiced by Vin Diesel). The gang is in the midst of a job when they face an interdimensional creature. Gamora (Zoe Saldana), Rocket Raccoon (voiced by Bradley Cooper), and Star-Lord (Pratt) all have brief moments to shine, fight, or crack wise, but Groot steals the show by firing up a Walkman and dancing throughout the entire thing. It’s a strong start, with Gunn calling back to the original’s opening while emphasizing that there will be even more silliness this time around.

A movie that’s trying to be about family

After facing the creature, the Guardians head back to their current client to cash in. That client is Ayesha (Elizabeth Debicki), leader of The Sovereign — a genetically perfect and excessively obnoxious race of beings covered completely in gold. And while the Guardians may be heroes, they’re also dumb heroes, and after they refuse to turn over all of the goods the Sovereign hired them to find, they’re suddenly on the run in a wild space chase. A bearded man named Ego (Kurt Russell) comes to their rescue, and after the threat has passed, he reveals he’s Star-Lord’s father. Reunited with a parental figure he’s never known, Star-Lord decides to stay on his dad’s planet and learn whatever Ego can teach him, even if it ends up pushing the other Guardians away.

That’s a very broad-strokes look at the film’s setup, but it establishes the most important thing: this movie is trying to be about family, whether it’s the ongoing battle between Gamora and Karen Gillan’s Nebula — feuding daughters of the supervillain Thanos — or the unlikely paternal side of Yondu (Michael Rooker), who bonds with Rocket over the course of the film. The themes aren’t exactly subtle, particularly given some deception going on, but it gives the film a thematic cohesion. Which is welcome, because otherwise, the movie feels scattered and rambling.

Multiple storylines interweave in a way that may have looked Empire Strikes Back-sharp in an outline, but in practice, it’s painfully awkward. A major issue is that none of the characters are particularly endearing this time around. Gamora and Star-Lord’s slow-burn chemistry is still there, but it’s sadly dialed back to make room for Gamora’s relationship with her sister — and Gillan once again delivers the weakest performance in the ensemble. Yondu’s storyline fares far better, with Rooker adding some unexpected depth to the mercenary as he struggles to redeem himself for past misdeeds, but there’s only so much the ancillary players can do when the heart of the movie is so painfully, soul-crushingly inert.

That would be the relationship between Ego and Star-Lord. While Russell is a high-five fan-dream of a reveal when Ego first arrives, the entire father-son storyline sidelines Star-Lord from the movie almost completely. He simply hangs out, utterly passive, and does whatever his dad says, while backstory and plot points are doled out around him and other characters try to give the movie a sense of momentum. Pratt is still engaging — Star-Lord continues to be the ultimate distillation of his movie-star persona, and even while neutered, the character still outshines Pratt’s performances in things like The Magnificent Seven or Jurassic World. It’s just that the movie lacks the combination of heart and spirit that made the original such a wonderful surprise, leaving the audience uninvested and waiting for the next joke to drop.

Comes together in the end with an effective emotional payoff

Thankfully, Vol. 2 does come together in the end with a powerful emotional payoff, but that’s only after it becomes a computer-generated action-fest with the fate of the universe hanging in the balance again. It’s the same kind of exhausting stakes-raising that nearly all Marvel movies rely on at this point, practically pummeling the audience into being wowed. And given the difference between Vol. 2 and the first installment, it’s hard to not notice the change in writing credits this time around.

The first film was written by Nicole Perlman, before Gunn joined the project and gave the script an extensive rewrite. Given that both writers received credit, a minor PR war ensued in the wake of the film’s success, with Gunn often claiming that he totally reworked Perlman’s script, while she implied that his work was perhaps less all-encompassing than he was claiming. In Vol. 2, Gunn is the sole credited writer, and all his trademark flourishes are there. The script is irreverent, the characters are sarcastic, and Drax the Destroyer (Dave Bautista) generates laugh after laugh as the hulking brute with zero self-awareness. But compared to its predecessor, Guardians 2 has a hollow emotional core, and the plotting feels clumsy. This movie doesn’t have any real purpose, even as a bridge to other chapters in the Marvel story.

Gunn can’t quite pull it off without screenwriter Nicole Perlman

That clearly isn’t much of a concern for the studio, as last week, Gunn announced that he would be returning to write and direct Vol. 3. I learned during my visit to Marvel Studios last week that an assortment of different personnel are involved in the studio’s creative process, and perhaps with the lessons learned from this installment, there will be a push to make the next Guardians of the Galaxy a little more worthwhile.

Don’t get me wrong. The new Guardians has some great jokes, and there’s a slow-motion moment set to Fleetwood Mac that almost lets viewers pretend they’re watching the original film again. And I’m sure it’s going to be the best space-opera you’ll be able to see in theaters until Valerian and the City of a Thousand Planets and Star Wars: The Last Jedi roll around. But given that it’s following a film that was so instantly iconic and unforgettable, it’s tragic that so many people are likely to forget Vol. 2 before they’ve even left the theater.