If you loved Doraemon: Nobita's Little Star Wars, try Doraemon: Nobita and the Castle of the Undersea Devil
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.

Doraemon: Nobita's Little Star Wars

Doraemon: Nobita and the Castle of the Undersea Devil
What they share
Both films are directed by Tsutomu Shibayama, and they both carry the cozy, playful, uplifting mood tags, and they sit in Adventure / Animation / Family / Fantasy / Science Fiction territory. If that's the register that drew you to Doraemon: Nobita's Little Star Wars, the second film will land in a comparable space — through a different lens.
What Doraemon: Nobita and the Castle of the Undersea Devil is
Here's another Doraemon movie, doing what they all do. Nobita and his pals embark on an underwater adventure in the Pacific. The bully, Gian, and his sidekick, Suneo, steal Doraemon's submarine to hunt for sunken treasure in the Atlantic. It's another entry.