The story concerns an engineer (Scalia) who is blamed for the disappearance of the submarine he designed, and leads an investigation team to the depths of the ocean, where he encounters an array of abnormal creatures.

However, this has been called into question, as Dino De Laurentiis had started developement on Leviathan before DEG's mounting debts forced him to relinquish the project to his brother Luigi's Filmauro in mid-1987.

[7][12] According to Coleman, the Italian mogul told him he had made both Leviathan and the lower budgeted The Rift to pull the rug from under the B-movie producers who had ripped off his past blockbusters.

[9] Leading man Jack Scalia had just suffered a setback after the sudden shutdown of a film he was shooting in Hong Kong, but received the offer to star in The Rift two days after he got back to the U.S.[13] He was cast after a single meeting with De Laurentiis in his office.

[16] Escrivá and Simon originally wanted Sergio Stivaletti to work on the film, and he agreed to design at least one of the creatures, but a scheduling conflict with The Church arose and he had to pass.

His team consisted of ten to twelve people, among them uncredited American technician Steve Humphrey, who had worked on previous De Laurentiis films.

[25] It is claimed in some discussions that the film received a limited theatrical release in the U.S. via Vidmark Entertainment on October 5, 1990, but no formal source could be found for it at this time.

[28] Nigel Floyd of Fear magazine dismissed it as "[a] by-the-numbers Spanish submarine adventure, whose belated entry into the [underwater horror cycle] only serves to emphasize its redundancy.

"[29] Leonard Maltin gave the film his lowest rating, stating that "[a]nybody who sticks around for the climax ought to be decorated for their trouble [...] As usual, R. Lee Ermey acts circles around most of his co-stars; but, ultimately, even he cannot sell this bill of goods.

"[30] The BBC's Radio Times called it "unfathomable junk with soggy suspense and damp drama" helmed by a "hack director" that "doesn’t have the budget, special effects know-how or acting smarts" to emulate its contemporaries.

[34] In his Horror and Science Fiction Films compendium, Donald C. Willis was mixed, crediting "some okay makeup and scenic effects", but noting a "functional, cliched story".

VideoScope wrote that, while it followed several underwater monster movies, Piquer Simón "succeeds in delivering what is probably the most enjoyable of the bunch", as he keeps the action "fast-moving" and "ladles on the gore" to get around his modest ressources.

[37] Ain't It Cool News complimented the effects, considering them "at least as decent as Deep Star Six and Leviathan" and concluded that despite being "full of action movie clichés", it was "a fun little ride".

"[3] Bloody Disgusting assessed that "[c]lunkiness aside, The Rift manages to be thoroughly enjoyable" thanks to "entertaining characters" and "[t]he creatures looking pretty good, all things considered".