It is correct grammatically although it needs a full stop at the end but it's not really a move tagline.

A tagline s a short pithy phrase that sums up the essence of a film without describing it too much.
Some examples:

Alien: "In space no one can hear you scream."
Boogie Nights: "Everyone has that one special thing."
Jaws: "You'll never go in the water again."

They are meant to intrigue you and make you want to find out about the film, but not tell you what it's about.

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I lack the imagination for a witty signature.