I'm rating this movie higher than it probably deserves for a couple of reasons. Firs, one has to admire the audacious, lurching combination of genres and plot lines, hallucinatory in their variations. Secondly, the final two shots of this movie are stunning. I won't give them away, although I wish I could because they are just some of the coolest final images of any science fiction movie of that era, and make the entire movie worthwhile.
All of these impressions reflects some advice I would give if you choose to watch this movie. I don't think one ought to watch it literally, as a plot-driven film, because doing so could be frustrating given some of the illogic and seeming randomness of the events. Instead, I ultimately watched it for the imagery, the drunken, staggering wackiness of it all, and the utterly fascinating cultural aspects of the movie (for example, wow, do Americans not come off particularly well in this flick!).
I would also recommend Genocide for those who enjoy eco-horror or eco-scifi, such as Frogs, Phase IV, Bug (the Bradford Dillman flick), Food of the Gods, and even classic giant irradiated "bug" movies such as Them and Tarantula, which were among the first eco-scifi movies.