Angst? What Angst?: Lola has been kept drug-addicted as a personal pet/slave for month, and it's implied that she's been his sex slave as well. Also, she was very nearly burned alive. However, by the end of the movie, she seems as chipper and upbeat as ever. It crosses into Fridge Horror, however, when remembering she and Leito are implied to have had a harsh early life: she might just be accustomed to that kind of things.
Awesome Music: "Determine" by Alonso, played over an extended introductory shot at the start of the sequel.
Complete Monster: Taha Ben Mahmoud from the first film is a brutal Parisian drug lord who kills anyone he doesn't like, especially his own minions. He controls the largest gang-run ghetto which the government walled off from the rest of the city to stop the further spread of crime. He's largely responsible for the deterioration in the district, but unlike the government he takes an active hand in making things worse by terrorizing the population to submit to his rule and dumping his drugs there. When a group of his minions fail to recover a large stash stolen by Leito, he shoots them in quick succession until one of them comes up with an idea. When Leito and his sister Lola almost have him arrested, he uses his power to makes a deal with the cops to imprison Leito instead. He takes Lola so he can keep her as a beaten, drug-addicted sex slave on a leash in his personal quarters. When a nuclear bomb goes missing and is found by his gang, he considers selling it to arms dealers before blackmailing the police and the government with the lives of 2 million people by aiming it at the city centre with a missile launcher. He chains up Lola to the missile for good measure so she'll be incinerated by the launch.
Critic-Proof: Received an awful critical reception in France (probably because the film toys with the country's social problems in a very politically incorrect fashion), but didn't do too badly in the box office.
Germans Love David Hasselhoff: The film was badly received by French critics, but was loved in the rest of the world, to the point to be considered one of the two foreign films that helped to dissolve the Chinese monopoly in the martial arts cinema (the other being Ong-Bak). Also, many Le Parkour practitioners from around the globe cite it as their gateway to the sport.
He Really Can Act: It's easy to forget you are seeing two stuntmen with little to no acting experience when you look at the charismatic Leito and Damien. The fact that David Belle and Cyril Raffaelli have done little aside of this work is quite a waste of talent.
Moment of Awesome: When Lola comes out of a drug induced haze on the roof, she notices she's chained directly below the bomb. Does she freak out and try to escape? Nope, she immediately tries to damage or disable the bomb.
What Taha does to Lola, getting her hooked on drugs and turning her into a human pet so he can frequently physically (and it is implied, also sexually) abuse her. When he grows bored of her, he makes sure the catatonic Lola will be burned alive.
How Leito kills the corrupt police chief in the beginning - by yanking his head through the prison bars (causing blood to pour from his ears) and then decapitating him by slamming his head down.
Relationship Writing Fumble: It really does seem like Lola was supposed to be Leito's lover, not sister at various points. At one point early on, she tells a mook who likes her moxie "sorry, but I'm taken"... and the only guy she's interacted with on screen was Leito.
Signature Scene: The opening chase/escape sequence is probably what everyone remembers the most about the film.
Leito brings Taha to the police station and fully expects the clearly corrupt police that has been neglecting District 13 for years to put him behind bars (with the additional hope that a powerful kingpin like Taha doesn't happen to have connections with said corrupt police). That someone as street wise as Leito thought so makes it even more jarring.
Minister of Defence Krueger's plan to wipe out the District 13 through the neutron bomb is just awful. It leans fully on the points that the bomb is still in the district and that Damien is able to reach it to introduce the code before the time goes out, so if the bomb goes anywhere other than District 13 or Damien fails at find it there in time, it all goes down (possibly catastrophically so). The fact that he refuses to pay for the bomb is revealing: it makes clear that he expected Taha to reasonably abandon the sale and just let Damien introduce the code for free in order to save his life, but it also shows he never even considered that Taha might Take a Third Option and just send the damn thing away from his district.
He could also executed much more successfully his plan if the detonation code of the bomb had been a random number and not a mix of suspicious digits (the code of the district, the exact date, etc). Admittedly, Leito would have probably deduced it anyways thanks to the rest of tracks, but the code was still a vital clue.