Hey, cool. I actually managed to write something. This is the most I've written in a long time. But it's fairly obvious I've been reading and playing too much Halo.
0930 hours, July 15th, 2056
In the Nevada Desert / Somewhere
South of the Humboldt Range
The harsh sun beat down, causing sweat to run down his face, and into his eyes. The sting caused him to wince, and blink a couple of times, but he never took his eye away from the sniper rifle's sight. From his perch atop a rocky outcropping, he commanded a view of a large portion of the expanse below. Dotted with only a handful of large rocks, the desert valley didn't offer many hiding places, yet he was having a hard time finding his targets. To his left, a sudden glint caught his eye, and he swiftly pointed the rifle in that direction, scanning the area around a boulder with a large desert scrub brush growing beside it. He saw a small movement behind the bush, and tensed, pressing his finger against the trigger. Suddenly the large alien creature stepped out from behind the bush, pointing its weapon directly at him, but he already had the creature in his sights, and fired a shot that hit it just above the left eye, killing it instantly.
He exhaled, and added another alien to his mental scoreboard.
He made another quick, but sharp-eyed survey of the landscape, and, satisfied he had got them all, he began to hike down to the bottom of the ridge, to walk to the installation on the other side of the valley.
Update: 8:30pm. I wrote another passage, which takes place at a later point in the story:
1345 hours, July 15th, 2056
Inside the U.S. Naval Reserve / Nevada
The thick metal doors slid open in front of him, and before they were even half open, the "bullets" began to fly. He quickly sidestepped and pressed himself up against the wall beside the door. He readied his gun, and made sure the magazine was full, and then he quickly sidestepped over to the other side of the hall, firing a short burst at the nearest target along the way. He briefly stuck his head into the doorway, and examined the room. One alien lay dead on the floor, the one he had just shot. There were three more spread out across the room. He pulled his head back inside, and several shots hit where his head had just been. The strange energy projectiles made the wall warm. One of the aliens said something in their strange, warbling tongue, and he could hear one of them start moving towards the doorway where he was hiding. He leaned out into the doorway, and fired a five shot burst at the one moving closer. Four of the bullets hit the alien on the right side of he chest, and it fell to the floor and lay in a spreading puddle of it's own blue blood. The other two aliens made a shrieking noise, and began to fire at him, and he ran out the doorway towards a stack of crates, taking out another alien on the way. He ducked behind the crates as the last alien began to fire. Suddenly he noticed the letters stenciled on the crates, and realized he was hiding behind crates of weapons and ammo. Not the best place to be right now. He hastily ran out from behind the crates, and almost ran into the third alien as it came around the side of the crate after him. The alien shrieked and tried to grab him, but he landed a solid kick in its midsection, knocking it backwards. He swiftly brought up his rifle, and emptied an entire clip into the alien's chest.
Now that all the aliens were dead, he made sure both doors were secured, and sat down to rest and regroup. He opened up the weapons crates to see if there was anything he could use. It was mostly ammo in the first crate, and, luckily, the kind he needed. He ejected the empty clip from his pistol, and replaced it with a full one, and also took all the ammo he could carry for both his guns.