All You Need is Kill

As the source material for the film, Edge of Tomorrow, this is a short, fast-paced actioner. The book goes into greater depth with regards to the origin of the alien invaders. I don't recall any back-story for the Mimics in the movie but in the book, they are here for a reason - and it's not compatible with the indigenous life on Earth. I appreciated the small amount of time the book spent creating that back-story. It made everything else just a little bit more logical.

Another change the movie made was the setting. In the film, Tom Cruise and Emily Blunt are running around Europe with their starting point in London. The book takes place entirely in Japan. This change really made no difference to my enjoyment of either medium.

But the biggest difference between book and film is the ending. That HEA ending in the movie really bugged me. It almost ruined the rest of the film IMHO. The book ends very differently in confronting the protagonist with a difficult choice. A choice that must be made if humanity is to survive the Mimic invasion. Ok, maybe it doesn't make a whole lot more sense than the movie ending - but I happen to prefer a bittersweet ending to one comprised entirely of saccharin.