GTA: Cowboys and Pirates
There is an old legend about pirates coming back to life. You thought that these stories were just made up to boost the sales of saloons. Apparently, you are wrong and these pirates are not only come here to steal, but to feed on the living. You need to defend yourself till there are no zombies left. Some of them drop cash or weapons. You can only use one weapon at a time, so you drop the current weapon to replace it with another one. You can use the money you loot to buy upgrades. Make sure that you get them before they can even get close to you.