The first ten minutes of the Marine campaign can be found on YouTube. The videos starts off with a great-looking cinematic showing a Predator ship destroying a human ship. Your ship then drops onto a planet and you explore a facility while completing different objectives.
This video is taken from the X360 version of the game.
http://www.msxbox-world.com/xbox360/videos/view/746/Aliens-Vs-Predator.html
Here's a link to the vid. its not pulled off from this site.
guess that makes it brilliant then lol