I did it on hard, solo the first go-round, never died. When I found the body of the Guardian and saw the little cut-scene, I immediately took to a covered position with my Cydonia-AR3 and Gozen-C and proceeded to dismantle the oncoming waves. The auto-rifle made short work of the soft targets, while the Gozen destroyed the hard ones. Thought the mission was great - I just wish my freakin' Ghost would stop alerting the Fallen that I'm, y'know, there. I prefer to attack from ambush rather than head-on, and he seems determined to draw as many enemies to us as possible.