Disclaimer
This is a review of two movies due to how short both movies are. Both movies are related to Dragon Ball Z, and I'll review based on how well the plot, characters, emotional pull, scene quality, and creativity are set up. Each category can score a movie either two points, one point, or zero points depending on how well the category stacks up. I will not compare the movies to other media to score a category, only using other media or original source material for reference as an example only. Let's begin.
WARNING possible spoilers WARNING
So Super Android 13 begins with the crew out shopping, and then eating as a few Androids created by Doctor Gero's computer come to town. They blow up a building and Goku and Trunks leads them away. Android 13 shows up, and the fight continues. Soon the toher androids are destroyed and Android 13 absorbs their parts and enters a super form. Suddenly no one can even hurt this guy, until Goku summons the spirit bomb attack. Instead of throwing it, he absorbs it, and Goku destroys Android 13.
Broly the Legendary Super Saiyen starts off with a saiyen survivor visiting Earth and telling Vegeta to run a new planet for the saiyen race. Apparently the legendary super saiyen has appeared, though the plot in the movie lacks telling you that the "legendary" power only shows up every 1000 years, and Broly didn't go back in time or anything. Anyway, Broly is revealed (shocker) to be the legend, and then he loses control of his power as Broly's father tries to leave so Goku, Vegeta, Broly, and the others die from a large comet that is about to hit the fake planet. Broly kills his father, and continues attacking and hurting Goku, a person Broly hates as Goku's crying drove him a little mad while they were in the hospital being born the same day. Goku summons power from all his friends and manages to damage Broly tossing him in the comet as Roshi and Krillin saves the Z fighters with a space ship.
So are the plots good? Super Android 13 isn't bad, but it isn't all that great either. It is a functioning plot, but it isn't anything all that great either. Broly's story however does have a lot of good writing, as the plot by Broly's father is interesting and only his lack of control on his son stops his plan from working. It is an interesting plot, even if the fight with Broly overshadows it slightly.
So is Android 13 and his gang good characters? Android 13 is, he understands a lot about himself and realizes how petty Dr. Gero's revenge plot is, but doesn't care either. His minions however, one doesn't talk and one is... kind of a silly racial stereotype. The short one is cool at times, but can still be a bit of an annoyance, and the other one, the big one who doesn't talk is kind of boring all together. Gohan does stand up to Chi-Chi though, but you will need to know about Dragon Ball Z before watching or be confused a little.
Broly's story is a bit interesting. He is absurdly powerful, but incredibly destructive as well. Similar to Juggernaut, even as a child he was nearly unstoppable. His father is cold and calculating though and is also an interesting character. Also Vegeta learns a bit and grows as a character in this movie, and it is interesting to see Goku being kind of the protector of North Galaxy. Plenty of good characterization outside of the villain.
Super Android 13 has some tense and dire moments at the beginning when the Androids are basically killing the entire city to find Goku and try to blow up the top of a mall. The action is also well done and the fights are wonderful. There is also a sense of dire when NOTHING can hurt Super Android 13 but they need to distract him so Goku can use the spirit bomb attack. Also, during the fight, Super Android 13 crotch punches Goku, dang that made me flinch. This is a movie with great action and some decent tension.
Broly's story also has some great action and some wonderful emotional pull by making you root for Vegeta to be the saiyen prince once more. Also Goku was pretty inspiring getting up every time his ass got kicked back down. While the emotional pull is pretty good here, it is slightly better in Super Android 13.
Super Android 13 was animated really well. There are no dark scenes and no real issues with the setting or animation. Broly Legendary Super Saiyen though has a lot of dark areas where the lighting of the scene makes some of the colors really weird. Also his transformation was weird as well as his skin peeled off in a green light to reveal his new "legendary" form. Also some of Broly's attacks looked incredibly weird adn were animated oddly.
The designs of the androids and their attacks are mostly creative and original. Android 13's design is pretty cool too, and when he absorbs the parts from his fallen comrades, he gains a super saiyen type of a transformation. the designs and the setting are pretty interesting and fascinating despite hoe simple they are. Broly's design is pretty cool, but his father's design is simple and bland, and the minions his father has are simple goons with unoriginal designs to them. Broly's super saiyen form in blue is interesting and his legendary form is massive and really well designed, and the setting is nice. Master Roshi's little comedy act was odd and unneeded however and only Broly's design was all that good compared to the other new characters (Goku and friends mostly looked and acted the same).
Again, you should be a fan of Dragon Ball Z and know a little about the lore before watching these movies. If you are into action then both these mvoies have in in droves. If you are into good plot and characters, Broly's movie has more of that, but Android 13 isn't bad here. The opposite is true if you prefer creative design and scene and animation quality.
If you like androids watch Super Android 13. If you like super saiyens watch Broly's movie. If you love Dragon Ball Z both of these movies are a good time.