It captures some aspects of several previous films; Solomon Kane, The Mummy, Lord of the Rings, although very loosely. The special effects are good and being a fantasy tale that of course is essential. There's too few fantasy films and it is a difficult balance of not being too childish whilst recounting tales about witches, ogres and dragons.
Other reviews are certainly very critical about the film, but as I say -- I found it entertaining. I came out of the cinema wanting to write another book, which is always a good feeling. Clearly, my creative juices were energised.
I think fantasy always gets a bad press. Did you notice that none of the Hobbit films were nominated for Oscars or Baftas? I wrote an article on why I like fantasy and linked that article to our ancestors. Romans, Greeks, Vikings etc who all told tall fantasy tales, so it surprises me that fantasy gets such a bad press. And yet, look at the success of the Lord of the Rings films. I think that deep down the popularity has never really waned.
Seventh Son is not going to set the world alight, but you may be surprised and like me, you might actually enjoy it.