Despite given more personality this time around, Broly still screams a lot and doesn't say a single word in battle. As the creators themselves said, Broly is a mutant by Saiyan standards and his version of a False SSJ is also identical to the Oozaru form in all but appearance. Lower level Saiyans like Broly and Goku can't control it because only the super elite, like Vegeta, were ever taught to do so — and obviously Broly didn't have this luxury, as rather than be treated as a super elite, he was banished to Planetoid Vampa out of fear of his power.
Even more likely, Broly is the first Saiyan he met that didn't try to kidnap his son, murder him, murder his friend, murder random people on his planet, and take over his planet to make a wish for immortality. Broly was a good guy, something Goku figured out right away, which is why the usually fight-happy guy wanted to avoid this fight when Broly first left Frieza's ship. Of course he wanted the only other decent member of his species to call him by his birth name.
Combined with this, since literally every other U7 Saiyan Goku met had been evil (at least initially), Goku was likely ashamed by his Saiyan heritage. But meeting Broly, who was kindhearted from the start despite being a full-blooded Saiyan, Goku might have finally been able to accept that members of his species could be good, and weren't necessarily something to be ashamed of.
If Goku had any doubts about Broly being good, they would have been resolved the moment he saw Broly survive the Soul Punisher, which, as a reminder, will destroy evil souls.
Bulma wants the Dragon Balls to wish for exactly 5 years of youth so that she can keep her looks without people thinking she's had work done. It's possible this isn't the first time she's done this. This might be why she still looks more or less like her teenager self despite being at least in her early forties by now.
This is lampshaded by Goku in the original Japanese dub, who is promptly then thrown to the back of the ship by an annoyed Bulma.
Broly's improving combat abilities make total sense when you combine the two aspects of his training. He was used to fighting massive, extremely tough monsters, who required at least some of his powers. In contrast, his only sparring against humanoids was against his father, who had a (comparatively) very low power level. As he fights Vegeta, Broly's simply applying more and more of the tactics he used against monsters to his new, humanoid opponent.
Another reason Goku and Vegeta are only using up to Blue may be because they don't want to risk getting Delayed Onset Ki Disorder. Considering how much they fought beyond their limits in the Tournament of Power by using their energy in a reckless and excessive manner, it's no surprise they would get it after the tournament. For that reason they are only using the forms up to Blue in order to not recklessly use up their energy and potentially cripple themselves for life.
Also, unlike the Tournament of Power where they could safely fight all out against various fighters, they are fighting Broly on Earth. It's likely that they fear causing their powers to destroy Earth, plus since Blue is more controllable, they can fight without risk of power backlash.
At the beginning of their fight, Vegeta smugly notes that Broly will probably be a "good warmup". Notably, he says this only after he's landed a solid hit against Broly, with Broly immediately springing back at him. Given that Vegeta is so vastly stronger than all but a very small handful of opponents, it's entirely possible he thought his first blow would kill Broly outright, and was pleasantly surprised when it didn't.
For the most part, Broly doesn't use many ki attacks. This would probably be because Paragus isn't strong enough to have learned them since he relies on a blaster pistol, so he couldn't teach any to Broly. As we've seen from various characters throughout the years, fighters don't tend to figure out techniques they don't realize can be done. Goku didn't learn energy blasts until after he trained under Master Roshi. Master Roshi still can't fly, either because he doesn't wish to learn or just prefers to stick with what he already knows. None of the U6 Saiyans realized they could have been using Super Saiyan, let alone other transformations, until Goku and Vegeta showcased it to Cabba.
Goku easily fared the best against Broly one on one, contending at a level of strength that Vegeta got overwhelmed in even after ascending to God, but this makes perfect sense on closer examination — it's not a matter of power, but a matter of skill. Vegeta's certainly a masterful fighter, but his style is militaristic, straightforward, and leads him to directly clash with his opponent whom, in this case, outclasses him. Goku, however, is a proper martial artist, having studied under five different masters, and his form, especially when grounded, turns Broly's clumsy rampaging against him with plenty of weaving and misdirection. The animation highlights this as well, Vegeta's battle more reminiscent of the rigid style of Z, while the flow and bounciness of Goku's movements evokes moreso the original Dragon Ball.
Vegeta takes a long time to rejoin Goku in the fight against Broly, even thought Goku was getting beaten pretty badly and seemed close to passing out at one point. This could just be because of normal Saiyan pride and such, but earlier in the film Vegeta was worrying that Frieza was going to reach an even stronger form than Golden and come back to have his revenge. It's possible he was trying to conserve his strength because he thought that once Broly was defeated they might still have to fight Frieza. Gogeta did seem fairly surprised when Frieza dropped out of Golden form and left without a fight at the end.
Goku intentionally led Broly into Frieza to buy time for them to practice fusion, because he knew that Vegeta would not be able to get it on the first try. Frieza is the best candidate because Goku just witnessed him take, in this order, Toppo's Destruction Sphere, a beatdown by the same God of Destruction Toppo and at least two brutal beatdowns by Jiren, the mortal stronger than a God of Destruction. This is on top of Frieza surviving being blown up with a planet, being cut to pieces and rebuilt into a cyborg, then surviving being revived in pieces. Since each failure was going to take a half hour (and Whis would likely lose interest in the first 10 minutes), Frieza was the only other way to keep Broly occupied until they could finally do it.
Super Saiyan Blue Gogeta easily overpowers Broly at max power, despite the fact that just before, the two were roughly equals as Super Saiyans. However, Broly's final form isn't a truly unique to him Super Saiyan form, but rather appears to be him pushing it to its pinnacle. In contrast, Gogeta jumps straight from Super Saiyan to Blue. Super Saiyan 3 is hundreds of times stronger than Super Saiyan, yet Super Saiyan God can clash with an opponent able to beat SS3 with a finger and Blue can match an opponent unfazed by a God punch to the face. Gogeta's power is astronomically higher as Blue than Super Saiyan, so him being able to take Broly apart is no shocker.
Paragus might've meant it when he said the collar around Broly's neck gives a 'mild' electric shock. Even the average Saiyan is leagues tougher than the average member of another race so an electric shock that would kill anybody else could just be a painful but survivable punishment for a Saiyan, especially one as strong as Broly.
In the modern time everyone in the Frieza Force is outfitted with variants of the latest model of battle armor (best shown by Berryblue and Kikono, who in the flashback wore armors based on the older model), but just some time earlier, during Frieza's invasion of Earth, only the elites and Sorbet wore those. They've had the time to produce more ...and now they've got many less soldiers to equip, given how Frieza wiped out everyone in the last invasion and they're struggling to rebuild to the point that someone with a power level of 4200 is treated almost as the second coming of the Ginyu Force, and they need to preserve them.
It's a common theme for villains in Dragon Ball material to parallel or reflect Goku in some way. However, in this film, it's Paragus rather than Broly who is the villainous reflection of Goku in a more subtle way: their relationship with their sons. Both Paragus and Goku had incredibly powerful, but kindhearted, children (in Broly and Gohan), and often coaxed them into fighting despite them not wanting to. However, Goku finally understood that Gohan didn't have his Blood Knight tendencies, and allowed him to branch off and live his own live while still encouraging him to keep training and getting stronger, resulting in Gohan being an extremely powerful but mentally-stable fighter. On the other hand, Paragus and Broly's relationship is what would have happened to if this wasn't the case: Broly has been raised to be a nigh-unstoppable killing machine, at the cost of being an emotionally-stunted wreck who has suffered a lifetime of manipulation and abuse.
It's been stated before that one condition in which a wish can't be made on the Dragon Balls is if the target of the wish is stronger than the magic that created the balls and refuses to go along with it. This makes Cheelai's wish for Broly to be moved back to Vampa succeeding curious, as Broly was in the throes of Unstoppable Rage through pretty much the whole fight, which became several times worse with Paragus' death. Except for the end when Gogeta launched his Final Kamehameha at Broly after overwhelming him in a Curb-Stomp Battle, causing a fear of death to come upon Broly which finally snapped him out of his mad trance — in the very same moment that she made the wish. Gogeta's beating of Broly was not invalidated by the wish; instead it made the wish working possible and quite literally saved his life.
Goku seems to have a bit of trouble transforming from God to Blue in this movie. Part of it is the different visual approach to transformations, but another part could be due to the fact that earlier, Broly used his ki to override Goku's God Bind, and thus possibly 'infected' Goku with it, somewhat. This is manifested not only by the out-of-place green color, but by the fact that during the transformation, Goku appears angry while his ki definitely invokes a raging imagery (much like Broly currently is)... and as it's been stated, Super Saiyan Blue requires perfect ki control and a calm mind.
It actually makes sense why Super Saiyan Broly is stronger than Super Saiyan Blue Goku and Vegeta. Since Blue is just Super Saiyan God going Super Saiyan, it means that the gap in their strength hasn't changed at all since Broly did the same by also going Super Saiyan in his Wrath State.
It is rather meaningful that after the Universe Survival Arc in which Goku, Vegeta, and several other characters kept breaking their limits. Their next opponent, Broly, is someone who keeps reaching the limits of his transformations' power, but not truly breaking them due to his lack of training and fighting spirit.
Broly is explicitly a mutant, but one of the interesting things about biology is that beneficial mutations are rarely singular - they have an effect somewhere else. In his Wrathful form, he has absolutely no self-control and is in an even more extreme form of normal Saiyan behavior. When he's calm, however, Broly is a perfectly Nice Guy who despises conflict, completely unlike the typical Saiyan behavior - whatever mutation made him didn't just make him stronger, it gave him different extremes of aggression; he has higher highs and lower lows of bloodthirst. He's a new subspecies of Saiyan.
Fridge Funny
Frieza no longer wants immortality because his time in hell has made him realise there's such a thing as a Fate Worse than Death. Might seem like Character Development at first, but think for a second — what's the alternative? Dying and going back to that very same hell, meaning Frieza would consider conventional physical torment worse than the teddies and fairies, so he really is just being a drama queen!
Broly doesn't know what water is when he drinks it. It's never explicitly shown, but he and Paragus may have been surviving off their own urine to survive.
It's possible they survived off the blood of the spiders or the snakedogs just like the former do.
Paragus had some water rations when he first arrived on the planet. Either it's been so long that Broly forgot what water looked like or Paragus kept all the rations to himself, probably to make Broly continue to fight the beasts of Vampa and get stronger.
It's also possible that it was used to extend their already-slim rations - stewing food allows it to last much longer than eating it whole.
When Frieza murders Paragus, he tells Broly that a stray energy blast killed him. For all Broly knows, he could have accidentally killed his own father; if he's actually operating under this assumption, then that adds an even more tragic layer to his ensuing meltdown.
At least in the Italian dub, Frieza quips that obviously Goku's stray blasts killed Paragus, thus shifting the blame on him and sparing Broly some of the guilt.
In the French dub it's the same as the Italian dub just above.
Given their desperate rations situation, its entirely possible Paragus ate Beets after killing him, or worse, fed him to Broly.
More like Fridge Sadness, while it's easy enough to make friends with Broly. It would likely be hard for Goku, Cheelai and Lemo to integrate him into a society like what's on Earth. Broly has been stranded in exile most of his life on Vampa with no one but his father for company. Not only that, but Paragus likely never taught Broly reading, writing or even basic arithmetic. No doubt Broly would likely also have several phobias, like Demophobia.note The fear of crowds of people. People with this fear avoid places that are known to be crowded places or heavily populated. Or the very similar Agoraphobia.note The fear of entering open or crowded places, of leaving one's own home, or of being in places from which escape is difficult.
With the canonization of Broly, it's highly likely that he's still stuck on Vampa in Future Trunks's timeline (or any other timeline for that matter) and with no Frieza Force to find them, he's stuck even longer in that hellhole. The only question is if anyone else could find them — such as Future Trunks after being informed of his existence (in Dragon Ball Heroes) — and if they meet would they be forced to fight, since Future Trunks is Vegeta's son.
The inhabitants of the planet Vampa are already terrifying in themselves, but they get even worse when you realize that Paragus with 4,200 of power apparently was not able to beat a bug. Although the protagonists long ago managed to overcome that power, we must not forget how terrifying a guy with that power level used to be. Nappa, who is slightly stronger than Paragus, destroyed a big city by simply raising two fingers, and laughed at the attacks of the most powerful earthlings, to the point that he seemed invincible. Vampa is full of creatures that are probably stronger than him.
Even assuming that Paragus could have beaten the bug, he mentions that a power of 920 is not enough to beat a bug. Which is still very high by human standards. Goku who fought against Raditz, who by this point had won the martial arts tournament, only reached that power using a concentrated Kame Kame.
While undoubtedly an awful father who prioritized revenge over his son’s wellbeing, Paragus’s situation certainly isn’t one many would envy. Imagine your own son being shot into space because of an absurd power level that is beyond anyone’s control, and when you go to save him, you’re stranded on a barely hospitable planet infested with giant monsters with no means of escape, and you spend the next forty or so years trapped there, struggling to survive and presumably not even having access to fresh water, with the only company you keep being your volatile son whose powers present a danger to you and himself in the instance he loses his temper and who also has no real idea of how truly awful your situation is because the prison you’re trapped in is the only home he’s ever known. It’s no wonder that Paragus seems to have a few screws loose by the time that Cheelai and Lemo find he and Broly: it’s possible that the thought of getting his revenge eventually was the only thing keeping him sane!
There are a few disturbing ideas behind why Paragus cut off Broly’s tail. Considering how powerful Broly currently is, it’s unlikely that Paragus would have been strong enough to cut off his tail by force. Which leads to two equally horrible possibilities:
Broly “agreed” to remove his tail, meaning that Broly, misguided by his devotion to his father and perhaps feeling guilt over his Power Incontinence, allowed himself to be mutilated in an effort to protect them both.
Alternatively, it was unwilling, but Paragus did it when Broly was a child, and therefore weak enough that Paragus could do it against his will.
A bit of Fridge Logic and Fridge Horror (maybe Fridge Humor for some). After Goku and Vegeta teleport away to learn the Fusion Dance, Frieza is being attacked by Broly the entire time they are gone. Not even counting how long it would take for Vegeta to learn the dance, they fail twice and each fusion takes about a half hour to dissolve. There also used to be a rule that two people would have to wait an hour before they could fuse again, but this may have been ignored. As a result, at a minimum Frieza was being smacked around for a little over an hour, while at maximum he was being attacked for over three hours, but the scene was mostly played for laughs so the timing may slip past a lot of viewers.
It's possible that, rather than strictly abiding by those time limits, Veku instead simply went Super Saiyan 3 to burn off the fusion time like Gotenks does, then Goku and Vegeta took Senzu beans to regain their stamina and breeze off the recovery time.
Except they couldn't here. When the two teleport to Piccolo, Goku asks if he had Senzu beans, and Piccolo said he didn't have any.
