Although I found the involvement of extradimensional aliens disappointing, the interpersonal dynamics as well as the action made it more than satisfying.
Excellent screenplay, excellent effects, excellent performances. Jeff Bridges, in particular, was an outstanding though not surprising main villain. All around an excellent movie. I can hardly wait for the sequels.
As horror goes, this was poorly conceived. Think about it: Why would natives be afraid of a carnivorous plant when it seems content to stay in & around an old temple. Besides, how long could such a plant live without "nourishment" (flesh!)