Can't really give this a good grade....
When i started playing this game, i thought it was pretty decent. but as it went on, with the repetitive kills, the simplicity, and the incredibly short levels, i began to realize that this was vastly terrible.
One complaint is the weapons. I played the whole game with the pistol alone. it is more useful than the shotgun and the assult rifle, and with the unlimited ammunition, and it only taking three shots for a successful kill, it is too easy to use. The shotgun, only taking two hits to use, and with limited ammo, was just plain terrible. It was slower, and did not cause "splash" damage of a typical shotgun. The assult rifle, or "machine gun" as it was called in the game, was horrible. It was faster to fire the pistol, and the assult rifle needed four successful hits to make a kill.
The zombies themselves were just plain dissappointing. The moved slower than the character, making any attempts at your life by them fail. A little backpeddling is their bane of existence.
Many times, it was impossible to do anything to the cave. everytime i played, i was unable to seal it or enter it or do anything of the sort.
The most dissappointing fact was that the car, which im sure many players wished to drive, was undrivable.
The dialogue was utterly terrible. whether english is your forte or not, asking someone to proofread it would not take so long, and the outcome would be much better.
Over all, i give your game a score of one, and hope you can fix these flaws before your next game is released.