I have some incredible things to point out for only seeing the trailer 1x so far, and they are this: 1. The flood "hack" into living matter or, like the Keys Brain in Halo 1, into computer systems. With the cognitive (brain) power of the hivemind, could he bypass or rewrite Cortana's UNSC loyal code? Could he control or corrupt her? Cortana, as said in the book series, is a "smart AI". Her intelligence expands until she dies at the end of an approxamately 8-yr lifespan. Could she be smart enough to actively rewrite her own programming for the promise of power? (unlikely and out of character as it may seem) 2. Modern burst-fire weapons (Similar to the Halo 2 battle rifle) are all able to be easily converted to fully automatic weapons (such as the Halo 1 assault rifle, for example). The rifle in the video may be a battle rifle with assault rifle capabilities. I would also like different versions of guns that use the same ammo because the bigger the gun, the slower the walk, and it would open up a wide variety of new options into the games strategy. 3. I totally forgot New Mombasa had a space elevator! Can you fight on Mt. Kilomonjaro (in all of it's awesomeness)? 4. While writing I carefully analized the the Halo 3 trailer. The level of hints is adequate. I don't want to give my hypothesis away, but I think I have a (little) bit of an understanding of the game. 5. XTRA storyline paths!?!?!?!? (very very excited and confused)