I read the manga of ALL YOU NEED IS KILL. The EDGE OF TOMORROW was only a very loose adaptation of the story. They kept the time travel, but lost all the darker aspects of the character relationships.
As with most things, the book was better.
I'm just incredibly sick of Hollywood taking ethnic characters and casting them as some white person. Scarlett will just be playing basically the same person she does in AVENGERS. People are probably going to see this and mistake it for the Black Widow movie. Even Grace Park (Boomer/Athena in BATTLESTAR GALACTICA) would have been a better choice. She has experience in drama and playing a humanoid-machine.