It would have been great...
Okay. First off, I enjoyed this movie for what was, but when I first saw the trailers, I got the impression that the film was headed in a different direction.
In the comics, one of Doctor Strange's most dangerous adversaries was the villain called Nightmare.
To me, it looked like Doctor Strange was going up against him and was calling on Wanda to help him fight off Nightmare's evil.
That might have made a better film, having some of the fighting taking place in Strange's dreams.