If you loved Death Billiards, 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.
What they share
Both films are directed by Yuzuru Tachikawa, and they sit in Animation / Mystery territory. If that's the register that drew you to Death Billiards, the second film will land in a comparable space — through a different lens.
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.

