The journey of the “3 Ninjas” series is interesting to consider, particularly how it progressed over time. The first movie in the set remains memorable, even if it wasn’t a huge hit with critics; it has a distinct feel of the 1990s that appeals to many people. Rocky, Colt, and Tumtum are likable characters, especially when they're learning martial arts from their grandfather, Tanaka. Though the movie doesn't go deep into the training itself, it still holds a certain nostalgic appeal that makes it endearing and has turned it into something of a cult favorite deserving another look. The second film was acceptable but suffered because Rocky and Tumtum were played by different actors, which broke up the feel of the first one. Even so, the new performers kept some of the fun and entertainment going, though it didn’t quite live up to the original. The martial arts training still isn't explored much, but having the grandfather back helps connect the films together. The third movie tried to bring back the original actors to give a sense of familiarity, but viewers were confused by another round of recasting. While it included elements of Indian culture and indigenous heroes, the film ended up feeling corny and isn’t particularly enjoyable to watch again, with the exception of seeing the original cast together, especially the grandfather. The series really went off track with the fourth movie—a poorly conceived effort that brought in Hulk Hogan and someone resembling Pamela Anderson for a plot about taking over an amusement park just to make money. The choice of who played Tumtum was particularly bad, resulting in a disappointing performance. Rocky and Colt were reduced to minor roles, which took away from what made the three ninjas special. Changing the focus to a villain fighting the FBI felt like the absolute worst direction for the series, contributing to its cancellation and disappearance from view.

Source on TMDB