- Midway through Marathon Infinity, Tycho will get extremely angry at you for suddenly cooperating with Durandal. His reaction? "Prepare to drink vacuum, fool." He then promptly teleports you out into space. Where you sit. And wait. And shoot. Don't worry, Durandal will eventually save you.
- In this walkthrough, an attempt to grenade jump fails humorously.
LPer: We could take the long way... (grenade jumps, but fails to reach the ledge) ...or we could take the long way.
- Many of the quotes from the Marathon Trilogy. An example: "By the way, I had an accident with some defense drones while you were away. You might bump into a few of them here. Don't worry, they're mostly harmless; I don't think I gave them any ammunition for those grenade launchers."
- The screams that the BOBs make when you burn them, or other players. Funnier because Bungie encouraged players to murder the people that you were supposed to be saving.
- Also, 8-Player Co-op in a game meant for one person? When it's not a ridiculous and hilarious amount of carnage, it's pure awesomeness. Why did they get rid of 8-Player Co-op?
- From fan-mod Rubicon: On "Prize Payment Schedule", if you don't immediately cut the power, you can read some terminals that would be otherwise shut off. You might wonder if there's any useful information stored there...
Lysander: Good luck finding what you're looking for. I understand that certain items can be mighty tough to locate when you don't have the proper information.Lysander: No, there's no information on Achilles here. I don't know what possessed you to access this terminal.Lysander: I'll be honest with you: there used to be a map on this terminal, with the route to that thing you're looking for highlighted in bright purple. But since I'm being honest, I've also got to admit that I've removed all data pertaining to locations aboard this orbiting substation. Sometimes the truth hurts.
- Durandal's naming sense: when he and the S'pht take control of the Pfhor ship that attacked the Marathon, the S'pht rename it "Narhl'Lar" ("Freedom and Vengeance") as a profound statement on the beginning of their rebellion. Durandal, on the other hand, calls the ship "Boomer".
- On "Curioser and Curioser..." (M2), when Durandal's complaining about his plan to subvert the drones not holding out as long as he'd hoped because the Nar already did that, look closely at the image he shows you. That green thing that one of the Nar is holding is a sack full of drones.