In english "already" is almost exclusively used with present or past perfect tense. Hence, it should be "the film has already ended". It makes more sense, because the perfect tense is used to express the finished (perfected) state of something. Maybe in spanish it is different, but I don't clearly get what "ya terminó" means, since to my knowledge the tense "pretéritó indefinido" is used to express something in the more distant past, while this sentence does not have such a meaning, since "ya" refers to the more recent past. Even if "ya" can refer to the distant past, it should translate as "the film had already ended".
This is an example of American vs British English. American English uses the past simple ("did") tense in many cases where a British native speaker would use present perfect ("Have done") eg "Did you eat yet?" vs "have you eaten yet?" "Already" implies recent past to a Brit, so the present perfect would be correct for a Brit here, but Duo has chosen the American translation.