not bad as a basic
there were 3 problems: 1 bad grammar as said so much. 2 you need to pick up your books about gunss and a game is the farther you progress the cooler and better the weapons yours on the other hand got worse. and3 your story was a little lame and very few and unclear missions.
i would say work a bit more on it and add a few missions. cause a zombie shooter should not be over after 4 missions