It looks interesting. I have read a few Narnia books and know that Tolkien influenced CS Lewis, but I have not read LOTR/Hobbit.
If the Christian faith was as instrumental in the life and imagination of Lewis as it was for Tolkien, I would hope the film touches on that...
You should read Lewis’ Space Trilogy: ‘Out of the Silent Planet’, ‘Perelandra’, and ‘That Hideous Strength’.
The Screwtape Letters was dedicated to J.R.R. Tolkien.
The forward to That Hideous Strength cites The Silmarillion manuscript 30 years before it was published (posthumously).