If you loved Case Closed: Zero the Enforcer, try Detective Conan: Black Iron Submarine
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
You already loved

Case Closed: Zero the Enforcer
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Detective Conan: Black Iron Submarine
What they share
Both films are directed by Yuzuru Tachikawa, and they both carry the cerebral mood tag, and they sit in Action / Animation / Crime / Mystery territory. If that's the register that drew you to Case Closed: Zero the Enforcer, the second film will land in a comparable space — through a different lens.
cerebral
What Detective Conan: Black Iron Submarine is
Tokyo, summer. A distant buoy. Interpol's data hub goes live in the Pacific, but a shadowy group snatches a key engineer, and Conan smells foul play. Classic locked-room anime hijinks for the whole family.