If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
It's zombie hunting season! Stock up on that ammo and let the zombie massacre commence! Each zombie kill gives you money to spend after the hard days work of killing the undead. Use it to purchase guns to aid your slaying.
Press on the arrow keys to move, A key to fire. You can change weapons by pressing key 1 to 9 (after purchase).