ITT, post changes which you’d like to see for individual campaign levels.
I’ll start.
Dawn:
-on Legendary, instead of cryotube sequence, skip to cutscene
-on Legendary, instead of prying the door open, it’s already open and sucks you in when you approach, triggering a cutscene featuring Chief climbing up the elevator
-on Legendary, Chief does not get ambushed. Instead, the sword Elite patrols the area
-on Heroic, the boarding battle is a wave battle a la Cairo Station
Requiem:
-timed/infinite/repeteable checkpoints occur at the pass (before the investigate Forerunner structure objective appears on the HUD)
-fixed load zone bug that causes the weapon crates spawned from defeating the 8 Elite snipers to disappear
-defeating the 8 Elite snipers causes an UNSC Pelican to fly in and drop off 8 marines. You can choose to skip most of the level by getting in it (a cutscene similar to the CE E3 2000 trailer will show the marines doing all that work for you before succumbing to their injuries/being slaughtered by sword Elites at the end of the bridge. The Pelican will drop off Chief in the area where the Hunters are fought before being shot down by the Phantom) or march into the elevator with your marines, arming them with the weapons from the crates if desired
-defeating the second pair of Hunters that are dropped off by a Phantom (which is spawned by defeating the 8 sniper Elites) spawns a portal which allows you to take control of a Sentinel and fly through the level
-on the bridge, a gold Zealot may spawn in a random location before heading down towards the lower section. When he spawns, a timer will appear on your HUD. This Zealot will have unique combat skills and he’ll always spawn with a sword. Approaching him will cause him to berserk, rendering him 100% freeroaming. If you can get him out of this zone, he’ll follow you to the end of the level. If you try to use the Banshee against him, he’ll hide. If you can kill him before time runs out, the game will spawn a Scarab gun esque weapon somewhere in this area, which will carry over to the next mission if you complete the level with it obtained. It’ll be treated like the Target Locator; you can take it out by pushing up on the d-pad
Forerunner:
I’ll post more ideas if people are interested.