With a title like "Attack of the Killer Tomatoes!", anyone going into this thing would be expecting either a) a bad science fiction movie or b) a comedy making fun of bad science fiction movies. It's supposed to be a mix of both, with a dose of parody splashed in. Unfortunately, it falls flat very soon.
You're never supposed to take this movie seriously, I realize that, but you're supposed to think it's funny, right? I found only a few of the jokes or situations were funny (i.e, the side-by-side phone conversations, the Russian Olympic spy eating steroid cereal, Superman walking by Lois, etc.). "Attack of the Killer Tomatoes" strives to be a cult classic, but it doesn't make it. A cult classic is a movie that is so different that only a select group of people understand it (or a similar description). "Attack of the Killer Tomatoes" could be enjoyed by any 8-year-old with a bad sense of humor, so therefore, it does not qualify as a cult film.
There is one good actress in the entire thing: Sharon Taylor as Lois Fairchild. She is a thin, gawky reporter, but has an endearing personality, loves to overact, and is a natural comedienne. Unfortunately, she is put to bad use here.
"Attack of the Killer Tomatoes" is not as funny as, say, "Amazon Women on the Moon" or "Kentucky Fried Movie", but it does have a few hilarious moments, so I would still recommend seeing it once. Avoid the director's cut, it has interruptions by the producer of the movie and some supposedly "lost" footage dubbed in a pretend African dialect (it can be found in English on the out of print tape).