Described on the Vimeo website as "a timeless boy-meets-girl story, wrapped in a supernatural world," the movie had its world premiere Sunday night at the Tribeca Film Festival in New York.
It is now available to view online for $5 for a 72-hour rental.
Whedon is best known as the creator of the TV shows Buffy the Vampire Slayer, Angel, Firefly and Agents of S.H.I.E.L.D. He also wrote and directed the big-screen blockbuster Marvel's The Avengers.
Notable deaths of 2014 [PHOTOS]