The basic plot of the game is simple: kill zombies and loot houses to earn money and ammo, get upgrades to your weapons and refill health, repeat until dead or bored. The game features 7 playable characters, the Doctor note , the Ninja note , the S.W.A.T note , The Survivor note , John Gore note , The Clown note , and the Foreman note .
Once the player chooses a character, he then enters the first level, a street full of zombies and houses. Zombies can either walk in from the ends of the level, or dig up through the sidewalk to spawn. Occasionally a vehicle, such as a sports car, bulldozer, or helicopter, will appear in the level, which can be ridden to speed through the level and destroy any zombies in the way. You can also rarely find NPC survivors who will attempt to help you through the hordes, but they tend to have a problem protecting themselves.
Zombieville USA contains examples of:
- Artificial Stupidity: It's not uncommon for the Npcs to not notice the zombie eating their back until it's too late.
- Chainsaw Good: The chainsaw deals massive damage to zombies as well as immobilizing them. It's even more effective if used by the foreman.
- Cool Car: The vehicles that occasionally spawn.
- Crazy Survivalist: Presumably the survivor, his character select bio claims he has stockpiled baked beans and shotgun shells.
- Elite Zombie: The more durable zombies that spawn in later levels.
- Fragile Speedster: The fast zombies can reach you before you react and deal a lot of damage before you stop them, but it only takes one or two shots to dispatch them.
- Gatling Good: The third and final upgrade in the machine gun line is a rotary minigun.
- Katanas Are Just Better: A katana is the final upgrade to the melee weapon line.
- Kill It with Fire: The flamethrower leaves the zombies as nothing more than a tiny pile of ashes.
- Money Spider: All the zombies earn you money when killed, which can be spent on upgrades.
- Monster Clown: The character select bio for the clown says they are the only thing scarier than zombies. Averted in game though, the clown seems nothing more than mildly depressed at worst.
- Non-Player Character: Randomly found in houses with a random weapon and as one of the survivors.
- Properly Paranoid: The survivor knew a zombie apocalypse would come. He was right.
- Zombie Apocalypse: The setting of the game.