Plants and zombies aren't exactly what you'd call natural enemies, given the latter's single-minded hunger for brains and the former's complete lack thereof. Despite being brainless, plants apparently appreciate the hand that waters them, so when zombie hordes come to eat your brains, it's Plants Vs. Zombies. To protect your own grey matter, you create defensive fortifications around your house by cultivating a wide variety of cute, combat-ready plants to handle the goofy varieties of zombie attackers. Plants Vs. Zombies is solidly rooted in the tower defence genre, but it grows and branches in such a charming, accessible way that almost anyone can pick it up and have a lot of fun. The basic gameplay is pleasantly engaging, but it will take seasoned defenders a few hours before they can play legitimately challenging levels. Fortunately, Plants Vs. Zombies rolls out new units and environments at a good pace, and the minigames, puzzles, and Survival mode offer some clever and challenging diversions. It's a delightful game that is both addictive and accessible, and you'll never look at your garden the same way again.
The core action is quite simple. Your lawn is divided into a grid, and each square can hold one plant. Zombies shamble up the rows of the grid toward your house, and if they get past your defenses, well, you know. At the top of the screen there are a number of slots that house the various plants at your disposal. Setting a plant down in a square costs sunlight, a resource that falls intermittently from the sky. However, you need more sunlight than is freely available, so you have to plant sunflowers to generate more sunlight. During the first minutes of a level, it's a measured balancing act between building your sunflower ranks and laying down defenses to deal with the first few zombies. Your basic attack units shoot peas down the row that they are planted in, so you'll need one in each row before too long. As the zombies become more numerous, you bolster your botanical battalion with a growing variety of projectile launchers, defensive barriers, attack amplifiers, and one-use weapons of zombie destruction. After you've survived the final wave of zombies, you're rewarded with a new minigame, a new type of plant, or perhaps just a hastily scrawled note from your would-be assailants.
Variety and creativity take this basic mission structure and turn it into something special. Just when you've gotten your daytime defense strategy down, the zombies decide to attack at night and you have a whole new set of plants to manage. When you've taken care of the nocturnal nasties, it's back to the daytime, only now a few of your rows are taken up by your backyard pool (there are snorkel zombies). New units come along that fit the new environments, and this steady trickle of new elements helps keep the gentle difficulty curve from becoming dull. Still, tower defense veterans will have to endure a lot of simple, familiar action in order to find a real challenge, and the wait may prove too long for some. Fortunately, all of the units are cleverly realized and adorably animated. Happy sunflowers bob merrily as they fuel your defense efforts, and pole-vaulting zombies jog toward your house with gangly athleticism. From angry jalapenos to spacy wall-nuts, each unit has a great sense of personality, and the first time you watch a dancing zombie moonwalk onto your lawn and summon his garishly dressed backup dancers, you'll likely chuckle with amusement. The visual charm makes the game a pleasure to look at, and it helps keep things feeling fresh.