Not bad...
Nice and simple work man ... the game's idea is kool but the game itself is not attractive... in fact it is so boring that even my 8 years old brother hated it. I advice u to remake the game and add more graphics in it not just ,copy and paste, and u can also add more weapons ... in the end its all your style; But its ok ... you have done a nice work , next time just try to make a game more attractive and complicated.