3 overlooked sci-fi movies on Amazon that you should check out in May 2025.

      The only thing better than an excellent sci-fi film is one that you can stream for free, without needing a subscription. This month, you can enjoy these three underrated sci-fi movies available for free on Amazon Prime Video.

      Previously, Amazon offered these titles under the Freevee umbrella. However, with the Freevee brand now discontinued, you can now find these free films labeled as "watch for free." If you’re seeking something in the sci-fi genre to watch without any cost (though with ads), you don’t have to sift through various options, as we’ve selected three notable titles for you right here.

      Looking for more suggestions? Check out the latest movies to stream this week, the top films on Netflix, the best picks on Hulu, the finest films on Amazon Prime Video, the top movies on Max, and the most popular films on Disney+.

      Dark Skies (2013)

      Produced by Blumhouse Productions, the studio behind many acclaimed horror films, such as Paranormal Activity, Insidious, The Purge, and Get Out, Dark Skies follows a typical suburban family who begins to encounter strange occurrences in their home. Their kitchen is oddly rearranged overnight, the house alarm sounds, indicating breaches at all entrances, and one day, hundreds of birds crash into the house.

      As bizarre events start to unfold around her family, mother Lacy (Keri Russell) investigates and suspects alien involvement. The film also features Josh Hamilton (The Walking Dead) and J.K. Simmons (Red One). Dark Skies delivers suspense and intrigue, even if the narrative occasionally loses its way.

      Stream Dark Skies on Amazon Prime Video.

      Leviathan (1989)

      Often compared to Alien and The Thing, Leviathan may resemble a derivative film, but it is worth a watch for those who enjoy a blend of sci-fi and horror. The cast includes Ernie Hudson (Ghostbusters) and Daniel Stern (Home Alone), and the plot revolves around an underwater mining operation that encounters a Soviet shipwreck named Leviathan.

      Leviathan is a gripping claustrophobic thriller, offering a mix of gruesome, frightening, and even humorous moments to keep you engaged throughout.

      Stream Leviathan on Amazon Prime Video.

      The Mandela Effect (2019)

      Recently, the psychological phenomenon known as the Mandela Effect has gained attention, partly due to Charlie Brooker's clever manipulation in the Black Mirror season seven episode Bête Noire. In this episode, two versions were released featuring different logos—one with "Barnie’s" and the other with "Bernie’s."

      This exploration of reality questioning is central to the 2019 film The Mandela Effect, where grieving father Brendan (Charlie Hofheimer) insists he remembers events and facts differently than what others claim or that appear to be true today. Brendan begins to believe he is moving through parallel universes and becomes fixated on the possibility that in one of these alternate realities, his daughter Sam (Madeline McGraw) is still alive.

      Stream The Mandela Effect on Amazon Prime Video.