The science fiction genre has provided moviegoers with some of the most ambitious, outlandish and thought-provoking material in cinematic history. A reliable source of thrills (and kills), the level of adventure that these type of films offer has allowed cinema to make incredible leaps in multiple departments - including story and special effects.
Unfortunately, being revolutionary can come at a cost, as the popularity of these ambitious offerings often results in studios going to the well again (and again and again and again and again). And as any sane person would know, going to there one too many times can sap even the most creative of wells, taking the fun and awe out of a story that was once truly great.
Yes, Hollywood's incessant desire to franchise everything is still capable of producing some real gems, but more often than not, it results in a truly outstanding film or two being followed by a host of uninspired sequels that threaten to taint the original's reputation - something that is particularly prevalent in the sci-fi genre.
With that in mind, let's take a look at some of the sci-fi sequels that failed be more than a major letdown.