The movie is worth watching if you like special effects with big animals. The script was written by someone in two evenings and was drunk while writing the ending. The beginning of the film and the end show us completely different characters who somehow use the same actors and use the same names. Their actions are often unrelated to what happened on the screen just 2 minutes ago.
There might have been aliens in this movie who could control human bodies. But if that's the case, then those scenes have been cut and now the film is incomprehensible.