Yes, there is a first one. But the first one was basic, not having much story to it other than unrealistic zombie-killing action. The second is more realistic. Garrett is me, Gabriel is a top-notch zombie hunter, Martin is a US marine. Martin used to have a friend, but he got killed in the first one.

Chapter One: Bruise
Garrett opened his eyes, getting a faint, blurry image. There was a blob of black, a haze of orange, and movement. Most of all, brown and green mixed in the foreground, and were moving at speed.
Garrett blinked, and the image became much more qualitied. The blob of black was replaced with the clear image of Gabriel, firing a pistol towards unseen enemies. Garrett thought of somthing, but he just couldn't figure out what it is.
He moved his head over to his left, seeing nothing but a mass of silver. He then heard a familiar voice say, "Hey, he's waking up."
The voice sounded friendly, but somehow concerned.

Garrett got up, seeing the brown and green form dirt and trees. The sky was gray, no sign of the sun. Smoke and fog made it difficult to see. Somehow it reminded him of somthing which happened recently.
Gabriel delivered a smile, facing Garrett, squinting. Behind him was Martin, who was firing in another direction. They were all moving, the sound of an engine roaring in the background.
"You were out for quite awhile," Gabriel said, nodding. "You can remember, right?"
Garrett could barely say much. He tried to get out a yes, but no sound came out when he moved his lips. Finally, he mustered out a, "Yes, but what's... going on?"
Gabriel sighed. He fired a short volley, and then looked down towards Garrett. "Well, its a long story." He said. He took a big breath, and then said what he had to say.
"You were talking to us, not watching where you were going... and you ran into a pole by accident. You fell to the ground, eyes closed, with a massive bruise on your head.
That might be why your confused. We took your gun and ammo, and stole this pickup truck. We're driving to the Atlantic, so we can find a boat to Europe."
"Wait," Garrett said. "The zombies moved out from the city that fast?"
Gabriel sighed again, and said in a flat, disgusted voice, "Yes."
Garrett's eyes widened, and he managed to stand for a moment. He saw that they were shooting at nothing, or at least it seemed.
He heard a loud bang behind him. He turned around, seeing the front of the truck. In the passenger seat, a man with a shotgun. The driver was another person, hard to distinguish.
It was easy to tell the driver was flooring the pedals, the gas meter just barely holding out.

UPDATE!!!

They were nearing the end of the fog, and things were getting much easier to see, and one could see much farther.
Now, there were at least three zombies. All were dreaded runners, but all seemed tired from running so fast. The one in the middle was somewhat menacing, holding two machetes. The final one was "ordinary", other than the sharp, long claws that Garrett had only witnessed in the video game Half Life.

The engine made one final putter before finally succumbing to the lack of fuel. The truck came to a screeching halt, then coasted alittle.

Gabriel reloaded the pistol, and took a few more shots at the creatures. A few hit the zombies, one in the leg, and another in its chest. "Its no use... we need something with more kick!" Gabriel said.
Garrett heard a crashing sound behind him. He looked, seeing the driver bash the window with the stock of an Assault Rifle. "I'm not sure, my M4 may seem like a good choice, but I need that for later." Martin argued.
"No, we need it now!" The driver said.

He opened fire, releasing a deadly volley of 5.56 rounds in the general direction of the zombies. Surprisingly, few hits were made, and the zombies were getting closer.

"Everyone GO GO GO!!!" Martin shouted, doing some kind of hand signal. Everyone started to run out of the truck.
Garrett watched in horror as one zombie did an amazing jump, leaping in front of the group, two machetes in hand.
It roared, and charged toward the driver.

"DIE!" He cried. Just as he was about to empty a clip into the creature's stomach, it used its swords to cut off the guys head. The M4 fell to the ground with a thud.

For a few moments, the creature barely minded the surrounding group, busy with its new meal. It pulled out a few organs, chewing them.

Gabriel was the first to try. First, he aimed his gun at the zombie's head, and fired a shot. The bullet made a killing shot. Then, he shot the driver to ensure he doesn't reanimate.

"Now that that's over with, where were we?" He said, before starting off with a jog. Everyone else following behind.