Red Faction: Armageddon

Did this on Black Market. Find a closed off room with only one or two doors and a ceiling(important since the aliens jump around). Make sure you have the magnet gun as one of your weapons. Step into the doorway and shoot at anything you see, if anything gets too close just hit it with the magnet gun and shoot it off into the distance. If you're getting overwhelmed you can just drop the walls and ceiling on everything(once again, magnet gun) and then repair them with left bumper. Definitely possible to do this solo but it goes twice as fast with another person.

This is simple. I have confirmed that you don't need to do it in one sitting. For example if you die on level 9 it's ok to restart level 9 and continue on. Also, if you're dead on level 10, 20, or 30 but your teammate finishes the level you will get the achievement.