A bigger budget and a better cast does NOT always produce a better movie. Such is the case with Return of the Killer Tomatoes. It's clear they have a lot more money to work with and have enlisted the acing talents of a young George Clooney [Return to Horror High, From Dusk Til Dawn] and John Astin [Gomez in the Addams Family] to improve the franchise. However, this actually makes for a weaker film. Here's why:
Part of Attack of the Killer Tomato's appeal is its bad acting and cheezy dialogue. It works because it's bad. Better acting actually takes a lot of the "funny" out of the movie. In fact, I found Return to be awfully dull, lacking much of the silly slapstick and parody that made the first film fun to watch. Return simply takes itself too seriously and suffers for it.
Furthermore, the plot is too complex for its own good. The simplicity of the first film worked in its favor. People turning back and forth from tomato to human form might be a neat camera trick but it's rubbish when it comes to the enjoyment of the film.
That's all I can really say. Enjoy the first film for its crazy, campy sense of humor. Skip the second and third altogether. There are much better movies out there to be enjoyed so why settle for poor cinema?
For more info check out the film's entry in IMDB.