If you loved Cat Soup, try Martian Successor Nadesico: The Motion Picture - Prince of Darkness
A bridge between a film you've already seen and one most people haven't. Martian Successor Nadesico: The Motion Picture - Prince of Darkness has roughly 10.4× fewer votes than Cat Soup — 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.

Cat Soup

Martian Successor Nadesico: The Motion Picture - Prince of Darkness
What they share
Both films are directed by Tatsuo Sato, and they sit in Animation / Science Fiction territory. If that's the register that drew you to Cat Soup, the second film will land in a comparable space — through a different lens.
What Martian Successor Nadesico: The Motion Picture - Prince of Darkness is
You return to the Nadesico crew two years after the war. Akito and Yurika are missing. A Martian splinter group attacks while Earth and Jovian forces scramble. The Hisago Plan’s Chulip portals unlock Bose particle power. Control means global advantage. The crew reunites on an unsanctioned mission. Prince of Darkness stays light on spectacle, letting character bonds drive the conflict home.