I haven't seen it, but from what I've seen I just don't think I'd enjoy it.
It looks too shallow and focused on being "cool" and "action-packed" for my tastes. More "Transformers" than "District 9".
I really love the idea of adapting fairy tales into action movies, but the ones I'm seeing are just so uninspired and lacking in the original magic and strangeness of the actual fables. Snow White and the Huntsman had some nice imagery and aesthetics, I also really loved the idea of a Joan of Arc styled Snow White and I think Kristen Stewart in armor definitely looked the part, but she unfortunately lacked the passion or substance to make it profound for me, which extends to the movie itself: it looks great but it's completely unsatisfying and forgettable.
Hansel and Gretel growing up and becoming witchhunters is an awesome idea and opens up so much potential for great conflict, such as in their hunting they come across a witch who actually isn't evil at all or even better: is morally ambiguous, making the siblings question themselves and their hatred for these women who use magic. Perhaps one of them empathizes with a witch while the other is still resolute in their contempt for her because she's still just a monstrous witch in their eyes.
But instead as I understand it the witches in this film are just evil monsters that the morally justified heroes get to shoot up.
Just seems boring to me.
Also I don't like seeing Jeremy Renner as a superhero or action hero :/