Unconscious inspiration for a huge blockbuster?
The alienated (no pun intended) child protagonist
The magical ability
Pursuit by "the man" of the children.
The use of special abilities to fly away from the antagonist at the climax.
The sentimental parting ending out on the mountainside with the spaceship being boarded, and... "goodbye" after the big hug.
I think these core elements are what made ET work so well, and I think they were unconsciously from this movie. You just rework these ideas into the narrative with a little lost alien.
(I also think "The Shining" takes from "Burnt Offerings". Both the novel and the movie.)