Simple Starling screenshake implementation - heavily cribbed from https://github.com/mikesoylu/fortia/blob/9347105789c2ac9e82109efab4ac44fa3511a7cf/com/mikesoylu/fortia/fScene.as#L89-L102

SimpleScreenShake.as

package {
  import starling.core.Starling;
  import starling.animation.Transitions;
  import starling.animation.Tween;

  public class Utils {
    // This function accepts an originalX and originalY so that you can shake things that
    // are on screen but not necessarily originally located at 0, 0 (compared to the original
    // implementation which only ever moved things back to 0, 0)
    public static function screenShake(drawable:Shakeable, shakeDuration:Number, intensity:Number, originalX:Number, originalY:Number):void {
      drawable.x = originalX + (Math.random() * intensity - intensity / 2);
      drawable.y = originalY + (Math.random() * intensity - intensity / 2);
      if(drawable.tween != null) {
        Starling.juggler.remove(drawable.tween);
      }
      var t:Tween = new Tween(drawable, shakeDuration, Transitions.EASE_OUT);
      t.moveTo(originalX, originalY);
      drawable.tween = t;
      Starling.juggler.add(drawable.tween);
    }
  }
}

import starling.animation.Tween;
import starling.display.Sprite;
class Shakeable extends Sprite {
  public var tween:Tween;
}