This movie is not a good movie, I admit that right away, so right off the bat let's not say I'm arguing that it's a great movie we should respect.
But that said the people who made this movie also know it's not a good movie. They are in on that and are just giving us a fun ride. I bet they had a lot of fun making it too. And I mean be honest what do you expect from a movie with such a ridiculously stupid title as "Return of the Killer Tomatoes?"
People playing multiple parts, laughably bad effects, stupid slapstick jokes, but it all works and is a lot of fun.
Plus George Clooney is in it, in what I bet is the role he is most embarrassed by in his entire career :) If you like "bad movies" that are funny it is worth checking this one out. Also the soundtrack is super fun.