If you loved Metropolis, try Woman in the Moon
A bridge between a film you've already seen and one most people haven't. Woman in the Moon has roughly 27.0× fewer votes than Metropolis — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by Fritz Lang, and they sit in Drama / Science Fiction territory. If that's the register that drew you to Metropolis, the second film will land in a comparable space — through a different lens.
What Woman in the Moon is
Apparently moon gold is a thing now. A scientist builds a rocket to fly to the moon. Lang's space romance is a bit of a messy launch.

