A proper Galactus could work on screen. It's tricky but if the execution is right, it could work.
comes to mind.
A comedy at heart but a great film that had a premise played completely straight and a tone that was completely grounded in our world. By the end of the film, the world is literally coming to an end and this is what our heroes are up against:
The film did such a great job at pulling the audience in, that by the time we got to the end, we completely bought into such an absurd concept, without question.