It occurred to me that both E.T. and Hansel and Gretel deal with themes of children versus adults and hunger of some sort. To draw such a comparison is, I think, no more or less odd than what comparisons I usually make.
Let's begin with the adults. I feel like Hansel and Gretel is one of those stories that most people know multiple versions of--most of the time we know that stories have multiple versions, but we're really only familiar with one or two. Red Riding Hood is probably the one we also all know multiple versions of. In Hansel and Gretel, sometimes the parents and children simply got separated; other times, they purposely left them in the woods. Sometimes they only left them temporarily, and sometimes they were trying to get rid of them. I think one version has the only the mother trying to get rid of them. The only version that this theme won't appear in so much is the one where the children get separated in an innocent way.
One way to see a story about children getting lost is that children should stay with their parents to stay safe. But when there is something sinister or untrustworthy about the parents, then the theme switches. Children become innocent and adults . . . are not innocent. This is what reminds me of E.T. In the movie, there is a sort of "us and them" about children and adults, even though not all the younger crowd always get along and some of the adults turn out to be trustworthy or helpful. In both stories, a child's innocence is more accepting, whereas an adult's greater exposure to the world has a negative influence.
Now on to the hunger. You've heard this interpretation of Hansel and Gretel, right? That it's a metaphor for gluttony or some such thing. The children are tempted by a house that they can eat, and the witch is a cannibal because she wants to eat them. You could, in turn, say that the theme of hunger is a metaphor for other types of hungers--like, say, the hunger of the scientists in E.T. They're not simply curious: they want to take control of everything and perform experiments and all that just to satisfy their hunger for knowledge and power. Like eating a house when you're hungry, there's a point where seeking scientific knowledge is justified--but there's also a line that you can cross to go too far.
You can describe both of these stories as magical, disturbing, and symbolic, depending on how you look at them. That's what keeps the interest in them alive: they're up for interpretation.