Yes.
Going back to the Alien reference above, the film was scary because you never saw the the thing. My poor terrified brain was filling in the gaps a man in a suit couldn't.
I can't remember who said it, but the key with storytelling is the mystery. The mystery is important, not the solution. The body in the cellar is dull once you know who it was and how it arrived there. Leave the thargoids as a bogeyman, a hobgoblin, something malevolent, mysterious and very much out there...
Like it, or not, they're coming.