The trajectory of the “3 Ninjas” series is interesting to examine, beginning with an initial entry that proved surprisingly enjoyable, despite not garnering widespread critical praise. It has a distinct feel of the 1990s that appeals to many people. The characters Rocky, Colt, and Tumtum are likable, particularly when they’re learning martial arts from their grandfather, Tanaka. Though the movie doesn't offer extensive martial arts instruction, it still possesses a nostalgic appeal that makes it a cult favorite deserving of another look. The second film was acceptable but suffered because Rocky and Tumtum were played by different actors, which broke up the original cast’s dynamic. Even so, the new performers kept the spirit of fun and entertainment alive, though it didn't quite reach the heights of the first one. The martial arts training still isn't explored deeply, but having the grandfather in the film helps tie the movies together. The third movie tried to bring back the original cast for a sense of familiarity, but the repeated recasting confused viewers. While including elements of Indian culture and indigenous heroes, it ultimately feels corny and doesn’t invite repeat viewings—aside from seeing the original cast members again, especially the grandfather. Things really went off the rails with the fourth film, which was a poorly conceived effort featuring Hulk Hogan and someone resembling Pamela Anderson in a plot about taking over an amusement park for profit. The choice of who played Tumtum was particularly bad, resulting in a weak performance. Rocky and Colt were reduced to minor roles, diminishing what made the three ninjas special. The decision to focus on villains battling the FBI felt like the nadir of the series, leading to its cancellation and disappearance from public view.

Source on TMDB