The story has been noted as "both a paranoid and a solipsistic fantasy", containing "the most complex discussion of those philosophical matters that have troubled [Heinlein] throughout these early years [of his career as a writer]."[2]
Gary K. Wolfe describes it as a "classically paranoid vision of the world", and states that the story only qualifies as fantasy because Heinlein does not offer any explanation of "who or what the Glaroon is and what its motives are".[3]
