Decent for 1 day
You should put more effort into making a game. You should probably get more of a plot going, better graphics with certain things, and make it more difficult. Maybe make it where it gets to a spot where you can use your pistol and in other areas you can't. So it isn't used for every single zombie you find, only for an area where massive waves of zombies are coming at you. Like if you were to go outside once the city was infested with zombies. Or have it so you have like 3 bullets in your gun at the start of your house, then leave and when there's a wave of zombies have it so you found ammo off a dead body or on the ground. So try to get more things to do, more time into it, increase a couple of things. And you just might get somewhere.