In this movie, Nobita and his friends encounter pirates while searching for treasure out at sea (not to be confused with Nobita's Great Adventure in the South Seas, where they also did that). In general, I think this one is pretty good. Gian and Suneo get to do something cool. The Mini Doras have a lot of screentime, which is usually a plus. Quiz the robot parrot, who speaks in riddles, is a fun character.
However, I have one major issue with this movie: the fact that about half of it is taken up by an overdone "Shizuka gets kidnapped" subplot. Not only that, but relative to the amount of time spent on it, this may be the most poorly executed arc of its kind in the Doraemon movies so far. First of all, the reason given for why Shizuka gets kidnapped is frankly very silly. It's because the pirates mistake her for their captain's daughter, Sarah, who supposedly looks a lot like Shizuka... except the two of them have completely different hair and eye colors. Both this and the fact that Shizuka doesn't seem to know any of her kidnappers should have tipped the pirates off to their mistake, but they never properly catch on. Furthermore, when we meet Sarah herself, there's absolutely no indication that she has a history of getting lost or running away, making it even more of a stretch for these pirates to immediately assume that she was the same person as this frightened, dark-haired girl that they encountered on a random ship. (One pirate does point out the hair color discrepancy, only to be hastily brushed aside.)
In addition, to facilitate this kidnapping, the filmmakers invoke Shizuka's disappearing weapon. Right before she is captured, the protagonists are engaged in heated combat against the pirates that have boarded their ship, during which everyone, including Shizuka, is clearly wielding a weapon. We even see Shizuka use hers (the Reversal Cape, to be specific). Yet in the scene where she gets kidnapped, she is suddenly left defenseless on the deck, with no explanation for what happened to her gadget.
Okay, let's pretend that the reasoning for and circumstances around the kidnapping do make sense. It could at least serve an important narrative purpose, right? Maybe it motivates the other main characters to go after the pirates, starting a new chapter in their adventure... Well, it does, but this turns out to be unnecessary. Shortly after Shizuka is kidnapped, the protagonists rescue a boy lost at sea, who turns out to be Sarah's brother, Flock. Having left the pirate crew himself, Flock also hopes to give his sister a chance to escape. That alone probably would have provided more than enough reason for the main characters to help track down the pirates, as it's unlikely (at least in the movies) that Nobita and his friends would turn down the chance to help another kid who is in need.
All right, but maybe Shizuka could make some valuable contributions by being among the pirates. Perhaps her bonding with Sarah becomes significant- Hmm, not really. Sarah is pretty much on the same page as her brother from the beginning. Well then, maybe Shizuka can use an outsider's perspective to help convince the main antagonist not to follow through with his plan- Uh, nope, that doesn't happen either. There's even a scene where she is the only one present in the same room as the main antagonist, but nothing of that sort plays out. The most plot-relevant thing Shizuka does in this movie (helping Nobita save Doraemon from being trapped inside an energy ball) occurs after she is already reunited with the others, so I am really struggling to see the point of the kidnapping subplot here.
To end on a positive note, I do like this movie's ending song. It has an unusual style for a Doraemon song, but it's got character, and I don't hate that it's become the current opening theme for the regular Doraemon anime series.
Tingnan pa 
