All I remember is these kids find a robot out in their barn. Then they have to battle this wizard or sorcerer.
At some point, there's papers flying everywhere. The kids are trying to escape from the house, and this chubby kid opens a door and there's a giant cheeseburger or something.
I think the title was two words, something like "close encounters" or "coming something"
The movie was in color, and probably produced in the late 80s or early 90s.