Castle in the Air is primarily a fantasy, but it contains elements from other novelistic traditions as well.

Features of the romance novel are evident in Abdullah's love for Flowerin-the-Night. Obstacles of family background and social status, like those Abdullah faces, are typically found in romantic plots. The unusual conflicts of personality, confrontations with danger, and exotic settings and customs that arise in Abdullah's pursuit of love also make his story one of suspenseful adventure.

Abdullah's story also contains hints of political intrigue. These can be seen in the troubles between Strangia and Ingary, and in the Strangian soldier's position as a cast-off war veteran wandering through enemy land. The novel also contains a science fiction concept of an alternate world, the one to which Hasruel exiles himself.

The fast-paced action and intricate plot twists that add excitement to these categories of novel are well represented...