Addressing the 'Sci-Fi' and Third Act questions

Rating: 7/10 (7 December 2014)

(Spoiler Alert)
This is not going to be a comprehensive review, but a response on two subjects. Whether the movie is sci-fi and whether it goes off the rails and has a 'meh' ending after a satisfying beginning.
Science Fiction has many facets, one being a love of actual science and seeing it taken to extremes, projected into the future, etc... Another aspect, which it shares with Fantasy, is that it allows a storyteller to get at questions that couldn't be realized in ordinary situations. The outrageous science element allows a human/ethical/moral dilemma to exist and keeps that from seeming outrageous.
From about 30 minutes in, Lucy knows she is dying and, despite the (spoiler) extreme transformation at the conclusion, she doesn't try to find a way to continue normally, or even super-normally.
I think the answer to both of these complaints exists in the nature of the conclusion. (Spoiler) This does not end in a 'human-centric' way. It does not end with boy/girl gets girl/boy or good guy beats/reforms bad guy, etc... Transcending even human desire for living is the solution Lucy considers superior. I mean if she can transform herself into a computer and see/travel through time, then she could probably repair or clone herself or come up with some other similar feels- better ending.
Some of the most classic science fiction explores the horrible situation where something essential is removed from a person's being. Frankenstein (yes it was science fiction. Biology is science, people) was conceived during the birth of electricity and discovery that man- controlled currents could move and affect human tissue/muscle. Dracula (a bit more of a stretch) was conceived during the discovery period of blood-borne diseases, disease transmission, blood transfusion factors, etc... Robocop, the Matrix, Total Recall, and many others examine the loss of self or some essential facet of humanity. Lucy chooses that loss of self and in that way makes itself stand out from other such films in a way that at least presents some interesting science fiction.
Was it the greatest science fiction movie of the year? Nope. Would it have had less appeal if not for ScarJo starring? Yes. Does Luc Besson have a hit/miss record with nothing in between? Yes, and this one is a soft hit. In the end, I know I'll watch it again at some future date because I know I'll re-watch a movie with an interesting theme more often than one that just flashes explosions on the screen.