Is the Shack a good Christian movie or is it heresy?

Not once in the entire Bible does God take a feminine form. He is called He for a reason.

Well it all depends, doesn't it?
Since heresy is defined as going against a doctrine of a given denomination, whether it is heretical depends on what denomination you are.

All of the heresies that "The Shack" is accused of are perfectly valid in at least one Christian denomination.

Universal reconciliation is a valid belief for modern Christian Universalists.
Denying free will is a valid belief for Calvinists.
Sola Fide is a valid belief for many Protestant denominations.
Many denomination reject the Penal Substitution theory of Atonement

The Shack has all these "heresies", but no one denomonation believes all these things. Which is why a Christian from any given denomination is going to find something wrong with the book.

...

Any follower of Christ would be outraged at this watered down, blasphemous, feel-good the-Bible-means-whatever-you-want-it-mean false gospel.
T. Baptist

I know, I'm more just poking fun at Catholics having a monopoly on calling things Heresy. His definition of heresy is correct though and the movie is probably garbage.