Peter Ericson’s review published on Letterboxd :
Quasi-philosophical action movies don’t come along very often. With "Lucy", however, writer/director/editor Luc Besson delivers the latest addition to that genre. The film is a moderate success, in part thanks to its at least superficially intriguing ideas.
"Lucy" starts off well enough. The first part of the proceedings is engaging, lets the viewer get to know Lucy (Scarlett Johansson), builds suspense, and offers intensity and a little gore. Occasionally, symbolic footage of one or more animals momentarily interrupts a scene. Then comes the second act, which is viscerally exciting and includes a cool car-chase sequence as well as scenes of Lucy making use of her newly acquired powers. The third and last act turns out to be the weakest part of the movie. As Lucy approaches the point where she uses 100 percent of her brain capacity, she effectively becomes invincible and consequently the level of tension drops to almost zero.
The film perpetuates the myth that human beings use only about 10 percent of their brains. This aspect of the plot bothered me to some degree, but with "Lucy" being a science-fiction movie, I was a bit more inclined to accept the conceit in question. To be fair, though, in defense of the film, one could argue that it is concerned with brain capacity and not necessarily with how much of the physical brain we actually use.
"Lucy" has an energetic style that keeps the viewer involved in the goings-on. Besson’s propulsive editing and the 89-minute running time result in a fast-paced narrative with nary a dull moment. Thierry Arbogast’s vibrant cinematography and the convincing special effects leave nothing to be desired in terms of the visuals. The musical score by Eric Serra has an appropriately futuristic, slightly otherworldly sound to it.
In the role of the eponymous protagonist, Johansson further solidifies her ability to play action heroines following her portrayal of Black Widow in the Marvel Cinematic Universe. She is really good here. As Professor Norman, Morgan Freeman gives a performance that he could probably do in his sleep; it isn’t bad in any way, just lackluster. Amr Waked has little to do in the role of Pierre Del Rio, while Min-sik Choi does a fine turn as Mr. Jang, the villain in the story. I noticed that Mason Lee, director Ang Lee’s son, makes a brief appearance as a hotel concierge early in the film.