Good, but fatally flawed plot

Rating: 5/10 (22 August 2009)

SPOILER ALERT! I am going to talk a little about the plot, so I am warning you that I might give something away in my review. Great movie, a lot of fun to watch, good action, good special effects. HOWEVER! Why did the aliens trade all their super cool, super powerful weapons for cat food? RIDICULOUS! The story shows the prawns being very quick to attack or harm humans. They are quick to be violent, and they clearly don't like being treated so badly. They are characterized by being involved in all kinds of sleazy behavior and crime, so why in the world would they willingly disarm themselves? They had to wait all that time until Wikus comes along and finally starts using their weapons against the humans to realize that they should be using the weapons? All that time they had been willingly disarming themselves, trading their weapons over for CAT FOOD? SERIOUSLY? That just did not make any sense to me at all. The movie is a lot of fun, lots of action, lots of gore, great special effects, good tension, good characters...but the whole time I was watching the movie I was asking myself, "Why did the aliens trade their weapons for cat food!" That made no sense. So I felt that was a fatal flaw in the plot. I just couldn't get past such an obvious flaw in story logic. I am surprised that the movie makers didn't ask themselves that while making the film.