In this movie, Nobita and Doraemon meet the pioneering settlers of a distant planet and protect them from an evil corporation that wants to mine the planet's resources. The story takes many cues from the space Western genre. This is an unusual Doraemon movie in a number of ways, probably due to it being such an early film installment in the franchise. Something that is well known to Doraemon fans is that the main characters tend to come across as better friends in the movies than in the regular manga chapters or anime episodes. (For example, in typical Doraemon stories, Gian and Suneo are much more likely to bully Nobita than to show concern for him.) In this film, however, the character interactions feel more similar to those in the mainline series.
There is also the fact that Shizuka, Gian, and Suneo aren't involved with most of the adventure in this story. Doraemon and Nobita are the only mainline protagonists present for most of the film, and much more emphasis is placed establishing their friendship with new, movie-exclusive characters. I can see how that could make for a compelling narrative to some viewers, but being generally more invested in the relationships among the series regulars, it didn't do too much for me. Be that as it may, it was nice to see Nobita's usual friend group get a moment to shine during the climax.
There is also the fact that Shizuka, Gian, and Suneo aren't involved with most of the adventure in this story. Doraemon and Nobita are the only mainline protagonists present for most of the film, and much more emphasis is placed establishing their friendship with new, movie-exclusive characters. I can see how that could make for a compelling narrative to some viewers, but being generally more invested in the relationships among the series regulars, it didn't do too much for me. Be that as it may, it was nice to see Nobita's usual friend group get a moment to shine during the climax.
