I've read a lot about how Merge Magic! is just Merge Dragons! - reskinned.
I would have to say that this is only partially true. The mechanics are mostly the same. It is in the levels that the greatest changes are apparent. Several of the pain points experienced in Merge Dragons! levels have been alleviated. Many of the goals are quite different, and obviously the layout of the fields is different.
So, problem solving is needed for the new problems presented.\
And the new artwork is refreshing - if a bit confusing! All part of the fun. ;-)