The lead designer of Alien: Isolation Gary Napper explained to GamesTM magazine that in the game you can get until the end of the story without killing anyone, although it will be a very, very difficult undertaking; Napper said the team felt that this could be an option to which the game's protagonist, Amanda Ripley, could use, and so they wanted to make it possible.

As we know, there will be only one Alien to infest the Sevastapol space station, but this will also be full of crazed droids and humans survived rather violent, so often the use of arms might seem like the only option, but it seems that is not so. It was not clear how you can complete the game without killing anyone-we imagine that we will have to give us to do to avoid enemies or even isolate them in areas of the ship other than that we're exploring-or if it also includes the Alien that will torment us in the game: we will end up without killing the alien?

Probably during the Gamescom I'll find out more.