So for those of you that have completed this seemingly impossible task, post here and let your unyielding might be displayed!
Also, I'm curious to hear what you think was the hardest part of the game.
For me the toughest part was on the last mission, the final standoff before the MAC gun. There were no good weapons, only assault rifles and shotguns, which are completely useless. I was thankful it was Brutes there instead of Elites otherwise my small reserve of DMR would not have been enough. And Emile wasn't around anymore to draw the enemies' attention away.
I was lucky that I accidentally swapped out my Drop Shield for a Hologram earlier because four Brutes dropped in right on top of me (another example of the bad checkpointing system), thanks to their simple minds, they chased my hologram as I sliced them with an energy sword one by one. If I noticed that I picked up the hologram, I probably would have never survived and had to start the level over, which would have sucked because it took me a little over 3 hours to reach that part.