B13 Ultimatum is simply a re-hash of the original B13, the latter merely serving as a stage for the incredible acrobatic stunts and action sequences displayed in the film. But, the sequel is a bit of a let down as the stunts seem repetitive after the first flick. The novelty has evaporated. Neither film has much of a plot, and in the sequel the story is similar to the first installment. In a near-future Paris, there is little distinction to be made between police and criminals, particularly in District 13. No one in their right mind would want to live in this place, and if you did you'd need advanced skills in martial arts and some high caliber weapons to survive from one day to the next. In both films crooked police elements are out to destroy criminal gangs in the city to increase their control, and are willing to sacrifice innocent people to accomplish these ends. In this improbable situation vicious thugs become heroes, of sorts, by thwarting police efforts. If you've seen the first movie, you've seen enough.
Review of District 13: Ultimatum
