Plants vs. Zombies is a tower defense game in which players protect their suburban home from waves of approaching zombies by placing various plants on a grid-based lawn. Each plant has a unique defensive function, from shooting projectiles to blocking or exploding, while different zombie types require specific strategies to defeat. The game spans five stages across daytime, nighttime, backyard pool, fog, and rooftop settings, with additional puzzle, mini-game, and survival modes.