Nick Vass’s review published on Letterboxd:
Is it discouraging to say I preferred the exposition on Planet Vegeta? No doubt, there's excitement in Broly's evolved powers ("Damn it! He's learning as he fights!"), but there's only so many screaming power-ups a Dragon Ball film can have. Maybe that's why I've dug all the economical episodes between Raditz and Kid Buu. Even with commercials, they range at just 20 minutes long, yet a feature-length can actually be prone to exhaustion.
Still, the breadth of Broly's genesis goes beyond any DBZ lore, and that's what I'm likely to recall. Revealing how the Saiyans were wiped out is an epic first in visualized form. Even if it's common knowledge that baby Goku was sent to Earth during the Supernova genocide. Among the vast barrenness on Planet Vegeta, and its gorgeously splendorous flares, is one of the visual standouts in DBZ to date.
The mythology just owns for all DBZ fans as well. From an almighty Frieza, the three Saiyan children, and the jealousy that transpires between King Vegeta and Broly's father Paragus over the banished fate of his insanely powerful son. Meanwhile, Goku's parents Bardock and Gena (which have only appeared in the manga) get a poignant rendition of sending their son to safety.
The sudden flash-forward montage is nicely done, too. Since it's not required to reiterate what occurred in between (the Android and Perfect Cell Sagas). As older Goku and Vegeta have a training session, it's not long until the Frieza Force go to Planet Vampa and rescue Broly and Paragus. [In this universe, Frieza has been reincarnated.] It's another sleek variation among the time gaps.
When Broly is brought to the Arctic, Goku and Vegeta square off against him. At least as a means for Paragus to enact his exiled revenge and have Frieza unearth Broly's powers. And by this point, an explosive power-up hysteria goes beyond any radar reading, which Broly somehow exceeds in real-time. [Keep in mind, he's never had a one-on-one before, just training with his father.] Goku and Vegeta turn SS2, SS God and SS Blue to initially test Broly, until altering vise versa.
Nobody will question the vocal energy through this extended battle. Yet it is fatiguing as Kamehama's, Instant Transmissions and Whizzing Discs make up feature-length form. Then there's the lamer DBZ segments that I never really liked as a kid (the impish banter, the wailing exaggerations) that just elicited some weak chuckles for me. Best laugh, though: the failed Fusion Dance as Piccolo gazes in embarrassment.
Special mention should go to how Broly's been envisioned now. As he'd only been known as a brutal, villainous Saiyan without an empathetic bone in his bony. Through a sins-of-the-father template, Paragus has exploited his son's powers for revenge on King Vegeta, all the more affecting since Broly cannot control his subjection. That viewpoint is retained in a vibrant, unruly Dragon Ball matchup. But as each new level is obtained, and the Arctic layers are smashed, I begun to feel wearier. The conciseness of a 20-min episode has always fared better for me.