The fantastic opposes the fantasy in that it starts from a realistic situation, then at a certain point, shifts into the bizarre, the strange, or even the irrational. On the other hand, the fantasy directly creates a parallel world (whether located in a fictional past, an alternate present, or a possible future) with its own set of rules. Science fiction, in turn, portrays a realistic world set in a possible future (anticipation) and/or a probable elsewhere (extraterrestrial). Lastly, retrofuturism portrays the future as imagined in the past, based on the principle that our current conceptions of the future will inevitably become retrofuturistic tomorrow.
The fantastic and science fiction (a possible version of fantasy) are not incompatible with comedy, even though these genres are rarely associated with comedy in theater, perhaps because comedy’s main device is to mock the real in its most trivial aspects and the human in its most mundane qualities. One can only laugh at a parallel world to the extent that it parodies our own. One can only laugh at extraterrestrials to the extent that they mimic our worst traits.