Yes, it's E.T. 2! Finally someone will tell us the rest of the story that Steven Spielberg so rudely interrupted!
So in this movie, E.T. 2, which must be called E.T. 2: Phone Home for contractual reasons (Just kidding: but it would definitely be the only possible bad movie E.T. sequel title!), we pick up right where we left off: the kids help E.T. contact his ship, and they foil the "men in black" guys to return him to his kind and finally leave Earth. Only his kind thought we had captured him, so they already "phoned home", and their home planet has already launched a planet-destroying missile that's too late to turn off or redirect or blow up. Oops! And so despite all our best efforts, Earth is destroyed, and it's all E.T.'s fault. (I knew he was a bad one from the moment I laid eyes on him! And there was never a sequel because they didn't want you to know the awful truth about this apocalyptic alien acronym!)
(Yet another edition of my original movie ruining sequels for great classic movies.)