As also happened with the 1990 book, some criticism was leveled by reviewers at the strangeness of the creatures showcased in Alien Planet. In his review of the TV special, Dwayne A. Day stated that "the animals are bizarre and frequently border on the implausible" and that "they do not appear to have been developed with a single biological theory in mind". Day also noted, concerning the scientists who talk about the animals as if they were real, "clearly some of them think that the animals that they are supposed to report about are barely plausible". However, Day also stated that the Darwinian creatures are though-provoking and that their strangeness is a good departure from the typical science fiction approach of making alien life look much like Earth life (such as using humanoid aliens). According to Day, the life of Darwin IV "makes the point that alien life, if it is detected, will challenge our abilities to understand and even comprehend it". A review in The Washington Post stated that "a few too many of the creatures seem like cartoonish monsters", though stated "but around almost every corner one encounters some sort of nutritious food for thought".