Hey, I used to hang out in these boards back in the mid-'00s. I'm dropping by again because I've started posting a fanfic retelling of the first (old school) Marathon game. It's told from the perspective of a BOB, so the main focus is on his struggle to survive an alien invasion without much in the way of weapons, training, or cybernetic enhancements. I always like exploring the grunt's perspective.
I try to stick pretty close to the lore. The biggest change is probably that humans don't have teleportation; I feel like that tech clashes a bit too much with the more grounded tech you see on-board the Marathon (the Pfhor do have it, however). I do take some poetic license with life on the ship and the colony, but there's not a ton of established lore on those to the best of my knowledge.
Anyway, hope you enjoy! I'm posting the story on the Space Battles forum. Most of it has already been written, and I do intend to write further stories for M2 and Infinity. No plans for third-party scenarios, even though I love them.