Modified

Micah walked throughout the floating graveyard carefully. He hadn’t seen any of the dead bodies from the previous crew, but he could sense they were somewhere around here. With no bacterial life forms to chew away at the crew’s carcasses, they would remain for millennia most likely. He dropped his helmet and held his gun with both hands, something was very strange.
There was static in his radio, he reached down and held it to his ear. “....Micah.....Get behind.........” he shrugged and continued on his way. As he entered a long hallway there was the sound of an explosion and as he turned his head the flash of light that engulfed him....

Micah gripped his gun wordlessly. He kept himself from panicking, because he knew it would take up too much air. Instead, he breathed slowly like he had been trained to do. He scanned his surroundings for the hundredth time. The dim light that entered the room was shown only by the sheer brilliance of the stars through the window; it touched upon the scattered adornments from what he suspected was the captain’s cabin. A couple of loosely scattered money chips, some blankets, two swords (one above the door, the other fallen from its place on the ground in the airlock wedged underneath the rubble that blocked it), a broken bed missing its mattress, and even a star chart and some paper and a pencil beside the remains of a desk.
He walked over to the window, precariously stepping over the items on the ground. He looked out it, the uninhabited, crater filled planet below, shifting slowly as he orbited it, alone, a nebulae in the distance, a couple of asteroids, and the stars. It was ironic, he thought, that the stars had been a source of such great delight for him when he was younger. Now, they were going to be his death.

It was the second day of his captivity in the iron prison. He had slept on the ground, propping his head up with a piece of clothing. He sweat profusely as the temperature in the cabin rose to above 90 degrees Fahrenheit as the ship hit the high time of its orbit, bearing the blunt of the star in the system. It was midday from what he could tell, so soon enough the temperature would be falling. He gripped his gun carefully and went over to inspect the entrance to his prison.
The oxygen in the cabin was limited, and if he could access the rest of the ship, that would fly well with him, even though the air supply would be used up. Rubble had buried him in the cabin, and for all he knew, the ship might have sent some others into the ship. If he could find companionship aboard the ship, or find some other souls that might even be survivors from the first wreck, that would help. Of course, many of things would help him in his current position right now. He focused his concentration on the rubble.
They were pieces of cement, which told him that the energy core to the ship was somewhere near. That scared him, the cement was probably oozing with radiation, but then again, he thought, there was no glow, and this particular class of ship had been out of production for almost half a century. If there was no large amount of radiation, the ship had probably gotten a new type of energy core.
He thought about it as he set his gun down to work his way through the rubble. Probably a fusion reactor. He nodded, he was almost sure of it. That was strange though, because the first efficient fusion reactors had come out a mere decade ago, and this ship looked to be over the better part of a century old. Micah stopped to scratch his head in curiosity and get a breath of air. The derelict was harboring some secrets he’d like to know.
He noticed the air was much thinner. He was using up dangerously large amounts of oxygen doing this. He took a minute to control his heart beat, knowing that if he got it too high, he would use way too much air. He continued removing the pieces of cement. Suddenly a current of fresh air hit his face, he had broken through!
He frantically scraped away enough of the rock so that he could get through. After spending a day and night and another half of a day in the putrid dungeon, he was sweating severely. Finally he picked up his gun and fired a charge or two into the pile. A shower of cement rained out outwards, and after putting everything of worth in the room into his pockets, he climbed out of it.
Micah picked his way to the bottom of the hill, and scurried along the wall. He checked his gun to make sure it was loaded, and began to explore. It was complete darkness here, and sure enough the energy core section of the ship had been blown through. Micah guessed that it was due to the meltdown of the energy core on his ship.
Luckily enough, a metal sheet covered the hole outwards, so the air stayed within the ship. He didn’t even test it, and pointed his gun to the ground. He slumped down, hot and sweaty. His combat armor hadn’t helped much, as they were not very efficient in keeping the heat out. He took out his comm unit tiredly as he swiped the sweat away from his brow, “Micah to Eagle Ridge. Do you read me?”
Static.
“Micah to Eagle Ridge!!! Do you read me?!!!”
Static.
“Micah to Eagle Ridge!!! Do you read me?!!!
Static.
His eyes got wide. He was alone, it was dark, he was hungry, they were dead. He took out a cracker or two from his small baggy, and chewed them as he tried to think it over calmly. However, he began to go mad. He looked around nervously, and frantically pulled himself up, taking his gun with him everywhere. He walked down the lonely hall, refusing to go into any rooms. If he heard so much as a sound he would turn around and point his gun everywhere at once.
Well, how long he walked, he knew not. His sticky hands grasped the gun tightly dropping it once or twice, and his hair got drenched. Suddenly, a green light went on behind him and distinctively beeped. He turned around and nervously shot a shot. The door closed tightly! Fluorescent lights blinked on. He must have walked into some kind of closet. They were trapping him, he knew it. They were playing a joke on him. “Okay guys, very funny.”
Silence.
“Guys?”
Silence.
“Guys!!!”
Silence. His eyes got wide again, and he began to breathe frantically. He was trapped in a small room. He could feel the air thinning by the second, he tried to slow down his heart rate, but to little avail. He walked over to the door, and banged on it. Nothing. The chamber he was in was little bigger than an elevator, and as he sat down and panicked, he began using up air. Well...seconds turned into minutes, and minutes hours, and hours days, for all he knew. He would calm down, only to get in a fright again that he was soon to die.
He tried firing his gun several times at the door, but it did nothing but char the door. He would panic, and calm down. fall asleep, and wake up in a panic. This endless cycle seemed like he was trapped in time. His sweat vaporized across the chamber, and a small cloud appeared above his head. It began to get hot, too hot for him.
He fired another shot at the door, this time it rikocheted off the door and went into the fluorescent light, shattering the glass. The green light beeped a couple of times, but then went out to. He was all alone, in total darkness. He fired at all the walls, and the only thing that happened was that a window opened from unseen hinges. He looked out it, there...there was absolutely nothing. They were out there somewhere, those who abandoned him. The ship was obviously not returning. He began to panic, knowing his companions were out there, perhaps dead.
Micah calmed down. The lights were slowly fading. There was a buzzing in his ear, but he ignored it. He fell asleep, and dreamt of his own funeral. He awoke in a fright, but calmed down. He wondered what the universe would be like now that he was gone, he wondered if he had made a difference, he wondered if...Suddenly, the lights all went out, and he slumped over.

“Look at this old ship.” the junior officer said as the two docked. “It’s the only one in the system.” His officer nodded. “Just go scout out the ship, radio back when you’re sure it’s safe.” He nodded. Once he got into the ship, he checked the oxygen levels. “That’s good.” he said, taking off his helmet and setting it down on the ground, promising himself he’d come back for it before he radioed the ship back. His Senior officer would be furious he was not taking correct security precautions, but he never had to know. As he explored the hall ways, debris was everywhere.
“Looks like the energy core malfunctioned.” he turned around, walking down a long hallway. He got to the end and knocked on it. There was a whooshing sound of air compressing, and the door opened. And there, at his feet, was a dead soldier. He backed off with a whelp, and began to radio in, when an explosion rocked the derelict...

Intriguing. Really intriguing... It's working well. Lonely, scary, dark... Yeah.

A few things... (And I hope you'll accept these comments in the spirit they are meant. To encourage, not discourage you.)

Air doesn't get thinner just because you breathe it. It gets fouler, making you sleepy, and causing you to make mistakes. The carbon dioxide you breathe out is heavy, so it would tend to gather at floor level first, although if you move around it'll mix in. (Firing a laser or heat-ray type weapon would cause oxidisation, and use up the oxygen faster.)

Also, it wouldn't be hot if the air pressure was dropping. A steady decrease in pressure would actually cause it to get colder, possibly dangerously cold. Ever fully discharge an aerosol at one go? They end up covered in frost.

I'm not sure you can put something 'on the ground' while aboard ship. You could place it on the deck - assuming that you're in an area with enough gravity or centripetal acceleration - or you could have released objects drift away gently, to emphasise the odd environment.

++ I look forward to the next instalment.

I guess ur right, i consciously forgot to explain that the artificial gravity was still on, and as far as everything else, I'll try to finish it up in my spare time.