The Zombies have arrived and they want your brains. Well actually they want your plants too. This is a classic "tower defense" style game and your goal is to protect your home from the hoard of zombies approaching from the other side of the street. Between the zombies and your home is your front lawn. Using the stylus, you place different plants in the squares of your front lawn by dragging and moving them. Different plants do things to help you protect your home in different ways.
In order to go forward, the zombies eat the plants in their way until either one of the plants (wall nut, potato mine, Venus flytrap, etc.) eats the zombie or the lawn mower mows them down. If the zombies get past all your defensive plants and the lawn mower, they get to your house, eat your brains, and you lose the game. It's not quite as simple as it sounds. In order for the plants to be available to use, you need points, and different plants will set you back a different amount. When a plant is available to you, it becomes highlighted, but it should be noted that you have to wait some time between placing each plant even if you have enough points to instantly purchase plants back to back.
As you gain experience by completing each game, you can plant new kinds of plants. Wall-Nuts can be used to bowl the zombies down in a game of bowling. Some flowers can shoot seeds at the zombies and kill them. Cherries explode like cherry bombs.
One of the most important plants you can grow are the sunflowers. Sunflowers release sunshine and you click on the sunshine to get points. When you have 20 different plants each doing its own thing as you're trying to tap all the suns so the sunshine is released and plant new plants to distract the zombies, it gets a bit hectic.
Each level has 10 games to go through before the next level and there are 50 different levels in total. At the end of each game you receive a tool like a shovel or a new plant is made available to you like a potato mine or snow pea to help you fight off the zombies in the next game.
During the game you also meet your neighbor, Crazy Dave, who gives you helpful suggestions throughout. As you earn more points you can stop by his house and purchase new seed packets, plants or garden tools.