Collect the falling sun from the sky to place plants. defeat the zombies using your plants. You can combine plants by placing them on top of each other. Every 15 seconds you will have to solve questions to continue. See how long you can last. List of combinations: Pea shooter + Sunflower = Sun-pea Pea shooter + Wall nut = Peanut Pea shooter + Cherry Bomb = Cherry Shooter Pea shooter + Pea shooter = Reapeater Pea shooter + Reapeater = Split pea Pea shooter + Split Pea = GatlingPea
