Mainly, it was poorly made and written. The spirit of the book wasn't kept. It tried to do everything and did nothing (or very little) successfully.

May I ask you friend why you think it was poorly written? And please be specific. I'm very interested to here this

VDT had the petentual to become one of the best loved Narnia films of all time but it fell short at many points.

The plot has many of you have already mentioned was bad even if we looked at as a stand alone film. This was enough to make half of the people embarrassed to even refer to this movie as Narnia. Because, C.S. Lewis would have never written a story like this. There were so many plot holes and bad script writing that it was hard to enjoy the movie, or even get attached to any character in the story.

I felt after the third time watching it in theaters it would improve my view on the movie, and maybe I had misjudged it the first two times, but that did not happen.

I loved the acting done by Will Poulter and most of the cast, but even they could not save the horrible script writing that went into this film.

It was mostly the inexcusable plot holes. If it weren't for the plot holes, the film would have probably been a bit better. For example, why did Rhindon glow? Was it powered by Aslan? The Seven Swords? And why didn't Coriakin offer to turn the Dawn Treader invisible? Was he selfish? Did it not work on things as large as the Dawn Treader?

On a side note though, the dialogue could have used a brush up or two. Some of it was "thank you , Captain Obvious" or plain stupid.

Theoretically, if you could divide the movie into book and non book elements, I'd say anything non book. Which means green mist related stuff I didn't like.