If you loved Ultimate Avengers: The Movie, try Batman Unlimited: Mechs vs. Mutants
A bridge between a film you've already seen and one most people haven't. Batman Unlimited: Mechs vs. Mutants has roughly 3.8× fewer votes than Ultimate Avengers: The Movie — 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 Curt Geda, and they sit in Action / Animation / Science Fiction territory. If that's the register that drew you to Ultimate Avengers: The Movie, the second film will land in a comparable space — through a different lens.
What Batman Unlimited: Mechs vs. Mutants is
You fight alongside Batman in Gotham as monsters overrun the city, but giant robot mechs join the battle. The Dark Knight's team clashes with oversized villains in a mechanical showdown, Curt Geda directs this animated action.

