Psychology and plot So first time writing a review. Before watching I wanted to quickly recap the original anime, though it happened to become a binge watching, due to the anime being quite well put. I had a few problems in the way they depict this guy, to fit the story.
I noticed that Light(in the anime), was the prep school student, with the all around advantages such athletic skills, the looks and to top it off was very intelligent. This means that the chances for him to become arrogant are very high. Since most people judge people, based on these qualities, in which he excels. So him viewing himself, as some kind of "god" and thinking he is better than anyone else actually make sense.
However, in the depiction of the character in the movie, he was the usual smart ass loner type of guy, that needed a confirmation of identity and support from a girl and even being pushed by Ryuk. This just changes everything, since he is somewhat being manipulated by Ryuk and the girl. Whereas the original Light is the manipulator.
The reason I am looking at the psychology of the characters is that the plot is so damn important, and lays out a foundation for things, such as Psychopathic and narcissistic tendencies Light has in the anime, which makes him unable to love anyone but himself. This also gives rise to answer the question that it makes sense for him to kill so many people, without flinching.
When it comes to L, he was surprisingly good depicted by the actor and seemed somewhat believable. So a big applause to him.
Of course, the movie seemed to be only made for monetary purposes. Would I watch it, if not for comparing the original? - I highly doubt it and would not recommend it. I was just interested in the what way the plot would be changed and it is not a change I approve of.