World Record VideosEdit
Halo Runs record page: http://www.haloruns.com/records?lb=101 (click the timestamps for video links)
Cryo Room/Tutorial (Easy/Normal Only)Edit
There are two small speedups to do during the training segment at the beginning of the level.
Performing the "look at the lights" test while using inverted controls is faster than doing it with uninverted controls; the latter will force you to re-do the test using inverted controls which costs time. If you are an uninverted player, it is still faster to do the test as inverted, then quickly go into the menu after completing it to change your controls back to uninverted.
After completing the shield test, the crewman next to you starts a conversation with Sam, the crewman in the room overlooking the cryo area. If you get close to Sam and look at him, he will turn to look at you and will end up skipping a few seconds of dialogue. You can look at him from the ground or from the upper grate platform.
It is possible to trigger the bridge cutscene early by entering the bridge area and then backing out. The exact threshold you need to cross is before the first left turn after passing the blue "Bridge" label on the ground. An example can be seen at 3:20 into this video: https://www.youtube.com/watch?v=wwPjDIn24PM#t=3m20s
Leaving the bridge after the cutscene as quickly as possible (moving immediately, not bumping into any walls or crewmen) will skip the trigger for the first wave of grunts outside the bridge. This also prevents you from getting a pistol, but it's still a good timesave due to the cafeteria door opening immediately instead of requiring you to kill the grunt wave.
In the room with the U-shaped staircase, it's possible to jump from the second half of the stairs directly up to the ledge above, saving a few seconds of running. It is also possible to grenade jump grenade jump from the landing halfway up the stairs to the ledge above, but is dangerous enough that it is generally reserved for Individual Level runs or segmented runs.
Maintenance Door SkipEdit
The first maintenance door you encounter is ordinarily locked for ~10 seconds while Cortana finishes some dialogue, but some checkpoint manipulation can allow you to skip some of that dialogue, opening the door early. The trick involves killing the 3 grunts by the door very quickly, and then getting a checkpoint in a precise spot, manually reverting to checkpoint, then proceeding to the door. An example can be seen here: https://www.youtube.com/watch?v=wwPjDIn24PM#t=5m30s
Level End TriggerEdit
The level ends when every enemy in the final area is dead, and the player enters the last open escape pod bay.