Eu encontrei! Decidi dar outra olhada e, por algum motivo, desta vez consegui encontrá-lo. Eu não tenho ideia do porque eu não o encontrei antes, porque eu acho que provavelmente foi um filme de Doraemon, mas não consegui encontrá-lo online em listas de filmes de Doraemon ...
De qualquer forma é Doraemon: Nobita e o Labirinto de Estanho !
Nobisuke watched a strange advertisement of a fantastic resort on television at midnight. Sleepy as he was, he made a reservation even though he didn't even realize he was talking to the advertisement. The next day he discussed with the family their holiday plans, only to realize that he could not find the place anywhere on Earth. All of a sudden though, there was a suitcase in Nobita's room and intrigued as he was, he opened it only to find a portal to the beautiful resort managed by tin robots. Even better, it is absolutely free. It seems that there is a hidden agenda behind the person who invited them here. As they go there they find out that Nobita and Doraemon are invited to stay in brikin hotel for free. They are enjoying and having fun but then suddenly they are attacked by the army of napo and the Nobita is saved by Doraemon but Doraemon is taken by the army. They ask him how he came here but when he refuses to tell and wants to go back to Nobita, they shut down Doraemon giving him electric shocks. Then the story takes a shocking twist.