On review aggregator website Rotten Tomatoes, the film has a 100% approval rating based on 23 reviews, with an average ranking of 7.7/10. The site's critical consensus reads, "As visually dazzling as it is thought-provoking, Fantastic Fungi sets out to make audiences see mushrooms differently -- and brilliantly succeeds."[4] On Metacritic, the film has a score of 70 out of a 100 by 8 reviews, indicating "generally favorable reviews".[5]
Critics praised Schwartzberg's time-lapse cinematography. Some critics found the narration unnecessary.[6][7]
Josh Kupecki of The Austin Chronicle said "visual affectations aside, Fantastic Fungi is an engaging look at the scope of an organism that is so much more than a pizza topping or an ingredient in beef stroganoff".[8] Andrew Pulver of The Guardian wrote "With its spectacular footage of growth and decay and impassioned speeches about the magic of mushrooms, this documentary is a treat for the eye and ear".[9] Rex Reed of The New York Observer called the documentary "charming",[10] while John DeFore of The Hollywood Reporter called the film an "[e]ye-opening eye candy".[6]
According to Robert Abele of the Los Angeles Times "it edges a little too close to being a commercial, but that's a nitpick when the totality of Fantastic Fungi is so entertaining, informative and appealingly hopeful about the hard-working cure-all for our ailing world lying beneath our feet".[11]
