Trivia: Near the far north side of the map there's a secret Forerunner door with a Halo: Infinite arcade machine inside. You can't play it.
Trivia: Right at the very end of the end credits, a patient document will appear from the office of Dr. Isiah Friedlander, Michael's therapist. The document gives an overall summary about what kind of player you have been throughout the game.
Trivia: On Eden Prime, the comrade who runs out and gets killed by the sentries is called L. Jenkins, a tribute to the internet video Leeroy Jenkins where a character on World of Warcraft runs into an enemy infested base and gets killed, along with the rest of his team.
Trivia: In one of the shacks, the devs hid an Easter egg referencing Back to the Future 3. In the shack, there is a tarp with the shape of the DeLorean underneath it. Also if you look in front of the DeLorean, on the table is the model train set similar to that of the train set used in the movie to demonstrate the time jump in Doc Brown's model.
Trivia: In 'The World That Never Was' you come across a type of graveyard with the headstones acting as gateways to each of Organization XIII's members' rooms. Each headstone describes their respective member with a depiction of their respective weapons.
Trivia: Intro Mission 2: In the second room you go to, if you go to the doors right next to the security drone you can hack and turn to your side, look through the glass windows of this door. You can see two doctors, a male and female, with arms locked and making out. A funny little Easter Egg the game developers placed there.