Final answer:
Stardust is considered a fantasy due to its inclusion of a magical quest and an alternate world inhabited by mystical beings, fulfilling classic elements of the fantasy genre.
Step-by-step explanation:
The movie Stardust fits into the genre of fantasy in several ways, but two distinctly different ways stand out. Firstly, its narrative involves a classical fantasy element of a quest, where the main characters undertake a journey through a world filled with magic, mystical creatures, witches, and pirates. Secondly, the film features an alternate world, the kingdom of Stormhold, which exists alongside the human world but is separated by a magical wall. These elements are signature tropes of fantasy, captivating audiences with their imaginative divergence from reality.