If you're not familiar with the Halo universe,
ODSTs are some of the most h4rdc0r3 d3wd5 around, second only to those big guys in faceless armor who keep appearing on the games' covers. The job description requires them to be thrown at a planet in a drop pod, and the survival rate is so low that it's all-volunteer. In fact, you have to be a Special Ops veteran just to have a shot at joining.
The main narrative of
Isolation starts with our main character, a random Marine, punching an ODST in the neck.
You know how when people start writing fanfic with original characters, their first urge is to have their OC punch canon characters in the snout to establish dominance? That's what I thought it was. The ficcer makes a big deal about how special Gui Montag is; he doesn't react like the other Marines when coming out of Cryo, escalates from the ODSTs rather caustic request to move to the aforementioned neck-punching, and when the ODST is about to retaliate, pulls a gun out of his locker, even while the narrative states that regulations say guns are supposed to be in the Armory. However, the story makes it clear that Montag isn't special because he's just better than everyone, he's special because he's a borderline psychopath with a death wish.
The story itself isn't without problems, though. It seems like every other paragraph is the author scoffing at the way "Hollywood" portrays Marine life. If could just be Montag--who is kind of a jerk--but it seems more like the author sniffing at how "unrealistic" the games are. The story takes place during Halo, yet there's no sign nor mention of the Master Chief, though SPARTANs themselves have been mentioned. And the author seems reluctant to swear. When I hear a Marine going "durn" it really messes with my suspension of disbelief. I don't swear in my writing either, but I try to eliminate the place where the swearing would be entirely, or at least come up with a decent substitute. (And yes, I noticed the hypocrisy. Thank you.) At least Montag's peers actually dislike him for his dickishness.
Bottom line: it's decent, but with a few minor irritations.