The cat and mouse game of Light and L works pretty well and is very entertaining, but the author reached the peak just way too fast. Instaead making the show 12 episodes, it is 37 episodes long. He solves this problem by various "Deus ex machina" moments, where something or someone appears completely out of nothing to enhance the story or to make a dramatic plot twist. As a viewer, I just feel cheated. This is poor storytelling. It's outright offensive at times. Considering this happens for a majority of the show, this is a big problem.
The highly praised of the show really is on a pretty low level. It's a very simple question in ethics and isn't even handled all too well. It takes an kinda interesting phenomenon but does not explore it. This is especially shown in poor characterization of the whole cast, which may appear cool in the beginning, but does not have a lot of depth in general.
Animation and soundtrack though are on a very high level. That may take a fun shonen show to an enjoyable level, but Death Note takes itself extremely seriously, therefore the focus lays on story and characters.
Overall it's a poorly written show which is extremely pretentious and is lucky to have a big fan base which protects it with all its heart.
