Although I didn't see this movie until the DVD came out, it is one of my favorites. This is definitely a survival movie, but completely different from most. In most "alien invasion" films, humankind is fighting the invaders to keep control of Earth. Think Independence Day or War of the Worlds. In "The Host," the war is over; the aliens control almost all the planet, with the few humans left free using guerilla actions to fight back and survive. It is a story of not only survival of the human race, but also of the aliens. Although they know that morally it is wrong to take control of human bodies, they must have a host bodies in order to survive. It is the internal struggle of one alien and its compassion for the human mind still trapped within the host body that makes the plot of the movie, along with the alien Seeker who is determined to find the remaining humans and either control them or exterminate them. In this process, the alien within the host falls in love with the humans in general and one human male in particular.
It is this love and compassion for the human race and the willingness of the alien to sacrifice itself to restore control of the trapped woman's body to her own soul that makes this movie so spectacular and different.
If you're looking for fast moving action and a lot of CGI special effects, you won't find it here. You will find a moving story of courage and survival, one of the most beautiful music scores I have ever heard by Brazilian composer Antonio Pinto, and an Oscar worthy acting performance by both Saoirse Ronan and Diane Kruger.