Once you've been paid for having taken down the first wave of zombies, you can use the money to buy new weapons. At the beginning, you'll only have a couple of pistols, but as you advance, you'll be able to get machine guns, grenade launchers, shotguns, and much more.
While at the beginning you'll only have to face basic zombies, you will soon be fighting much more resistant zombies who will make your life more difficult. In addition, any zombie that manages to get to you will mean the end of the game.
In addition to being able to choose your weapons at the beginning of the game, you'll also be able to choose what your character looks like. You can choose from different heads, torsos and legs, and you can even make a sort of Robocop.
Zombie Hunter is a very entertaining action game that lets you shoot at zombies without any remorse.