if you don't manage to get this one for some reason jump out of the game, restart the campiagn on the easiest difficulty and start again, this way it lessens the death factor and need for a restart in the checkpoint. all that's left is to get those 20 kills, if you don't have it by the time you're in the kitchen, start over. you will have to watch the cutscenes again, but you'll feel better as soon as you get that cheevo in your collection.
