Think back to that first mission. Think about some of the things you saw during that mission and never saw again... Can't recall? I'll remind you. Trip mines. Vast areas were enemies were literally crawling the walls. Enemies interacting with the environment all over. Additionally like so many have commented the mission is very unique compared to all the release ghost and protect from horde mission that follow. Edit 2: I can see a ton of people agree with this post so I'm adding a few hash tags to try and draw attention from bungie maybe they can see that there is something people genuinely would like to see more of! Why was this the only mission with features like this. Edit. I'd like to say thanks to everyone for their comments!