If you loved Kabaneri of the Iron Fortress: The Battle of Unato, try Kabaneri of the Iron Fortress: Life That Burns
A bridge between a film you've already seen and one most people haven't. Kabaneri of the Iron Fortress: Life That Burns has roughly 3.2× fewer votes than Kabaneri of the Iron Fortress: The Battle of Unato — 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.

Kabaneri of the Iron Fortress: The Battle of Unato

Kabaneri of the Iron Fortress: Life That Burns
What they share
Both films are directed by Tetsuro Araki, and they both carry the epic, raw, unhinged mood tags, and they sit in Action / Animation / Drama / Science Fiction territory. If that's the register that drew you to Kabaneri of the Iron Fortress: The Battle of Unato, the second film will land in a comparable space — through a different lens.
What Kabaneri of the Iron Fortress: Life That Burns is
You fight undead hordes in industrial revolution era Hinomoto, but then powerful armored trains become your lifeline. The director sets a dark fantasy tone.