Doraemon movies work because they let you believe Nobita's impossible dreams for ninety minutes straight. This one builds a real island, fills it with genuine danger and discovery, and animates it so beautifully you stop asking why the premise doesn't make sense. The character animation is sharp enough that even Quiz the robot feels like someone worth protecting, and the action sequences move with a clarity that most adventure shows can't touch. The plot collapses under its own weight by the third act, which is the Doraemon movie tax. What matters is that you got to explore an unmapped world with people you've known for decades, and that island is real while you're watching it.
Nobita dreams of finding his own treasure island, even though every corner of the Earth has already been mapped. Doraemon hands him a special map pointing to one, and soon the news reports a newly discovered island no one knew existed. Convinced it is his treasure island, Nobita brings Doraemon and Shizuka along on a ship Doraemon provides, and Gian and Suneo join the trip too. The voyage takes them into the Caribbean Sea, with Nobita serving as captain. As they close in on the island, a band of pirates attacks. Shizuka is carried off, a storm slows the rescue, and small Mini-Dora robots lend a hand along the way. When the group finally reaches the mysterious island, they find it is far from an ordinary one. The film is a comedic science fiction adventure.