The blurbs for the game so far mention that you will be crash landing at the colony of Hadley's Hope from the film. But, the game is supposed to be set after those events so how can you land at the colony if its been blown up by a nuclear explosion? Unless you land at the crater or something.
You are part of a rescue team sent to see what the hell happened. First you board the Sulaco which is in a degrading orbit around the planet. Then the Sulaco crashes into the planet and you start the planet-side mission.
This is all post processing plant explosion.
You'll never realize how great a weapon a Cardboard Box is until you are naked and it's all you have.