There was a lot that was good in the movie but it had two major flaws.
The biggest flaw is that if you're going to set up the story at the beginning with a lot of real-life issues that need to be resolved, then he needs to go back to Kansas at the end to resolve them. I'm all in favor of Oz being a real place, so he has to stay in Oz because Dorothy has to meet him there later, but if that's the ending you're going to have then you need a beginning that allows for that. The ending set up was one where he apologizes to his friend and proposes to the woman he loves. Smooching her avatar at the end does not provide the necessary closure.
There was a marvelous moral closure from the setup where Oscar tells the woman he loves that he doesn't want to be a good man like his father, he wants to be great. Then at the end of the film Glinda points out that through his experience he has learned that goodness is better than greatness. Lesson learned, but we needed to see it acted upon.
The other flaw was the actor playing the future Wicked Witch of the West (Mila Kunis as "Theodora"). Yes, it was a cartoon role with simple lines, but a better actor would have given it the range it needed, and the range that would have made it enjoyable to watch.
Her sister "Evanora" was better, but she kind of suffered from lack of plot. She didn't have enough backstory or motivation. Something missing.
There are parts of the story that just seem inadequate, like it was created without enough love.
Nothing was missing in the opening sequences. The movie was great and moved wonderfully for the entire in-Kansas part. Although you had to question whether the magician's audience really were so unsophisticated that he couldn't have just said said to the little girl something along the lines of "I'm an illusionist, sweetie. I don't perform miracles. I'm sorry." People nowadays don't expect magicians to be actually performing magic, but we love to watch them anyway. Was the 1890's audience that much different? But, OK, the action flowed through the Kansas sequences, so questions like that really weren't a problem.
The tornado scene was a lot of fun.
I liked the mechanical creation of magic as a solution to what seemed to be an impossible task. That was a great piece of the plot. The fog and mechanical robots to trap the evil flying baboons was a great idea. The projection of Oz in the cloud of smoke was a wonderful effect and fairly set up.
I loved the beginning with Kansas being both black and white and also a smaller square screen. Then Oz opens out as wide and colorful.
I did find the colors kind of not quite right. The look worked for the Alice in Wonderland movie, but it didn't please me as Oz. Of course, that's the set designer's prerogative. I did like the dramatic landscape, cliffs and trees.
The people traveling in bubbles was from one of the books. It was fun to recognize that.
When the movie came out I was afraid it would be Gregory Maguire's blood-soaked Oz. It was a relief that it wasn't.
The opening credits were great. The closing credits dragged, and the song changed before the credits were over from the waltz that fit the grand-retro mood into a contemporary sort of thing that didn't go with the mood at all.
Another thing that felt unresolved was that the Wizard had an entire bottle of glue. Why not look through the china town and see if there's anyone else they could glue together? I kept expecting them to get around to it and they didn't. They seemed to be setting it up with the china girl asking for him to grant the wish of restoring her family. But then they didn't do it. It seemed wrong.