So, I have mixed feelings about this movie.
I spent a good moment in theater and I was entertained, but man, it could have been so much more than this.
I know it's not fair to judge a movie for what it could have been rather than for what it is, but I'll try to explain.
Spoilers ahead.
This is a movie that starts with a very interesting plot based on a scientific subject - what if we could gradualy use up to 100% of our brain? - but it get sidetracked pretty fast with all kind of superpowers that you obviously could not have even if you could use 100% of your brain.
They sort of use the idea that the body evolves at the same time as the brain (here the brain can control the body to the point of changing form, controling other people's bodies, seeing everything everywhere, etc...) and at one point you don't even need the body and the concept of space and time does not apply to you anymore... Mmmmkay...
I could have deal with this if the drug Lucy took was from, I don't know... space! Or if the whole movie was totaly designed as a superhero movie. But the movie starts like if you are about to watch the next "Inception's smart" movie. And it is not that at all, no matter how hard Morgan Freeman is trying to sell you the scientific side of it.
They could have play it smart with a more scientific approach, and I'd have loved it. (I can imagine enough spectatular, amazing things one could do by controling 100% of his brain without loosing too much sens of reality)
They could have play it full science fiction/superhero, and I'd have loved it. (it's kind of what they did after all, but then I needed a movie more grounded in fantasy than in a pseudo reality).
But Luc Besson mixed the two in a way that... entertained me, I can't deny it (Besson knows how to make a scene work and Scarlett is good.), but that also made me think at one point: "Oh, ok. That is that kind of movie after all... Whatever, Let's go all superpower crazy!".
That's why I was at the same time pleased, but very frustrated.