Finally combining my love of gardening and my need to slaughter the undead, Plants vs. Zombies is a unique tower defense game from PopCap Games. First released on the Mac and PC in 2009, this cartoonish and addictive strategy game has been ported to the iPhone almost perfectly.

In Plants vs. Zombies, you’re a homeowner with a zombie problem. The undead want to invade your yard and get to your delicious brains. Your best defense is to plant peapods, mushrooms, squash, and other deadly legumes (deadly to the undead, that is) to fight back the zombie hordes.

The beautiful cartoon artwork is on the right side of zany and sets a light-hearted tone from the get-go. The zombies are silly, distinctive enemies that vary in character, from your standard groaning zombies, to zombie football players, Zamboni-riding zombies, zombie dolphin teams, and zombie balloon riders. Each has a distinct battle skill that you’ll have to confront.

As you progress, you’ll unlock an almanac explaining the abilities of your plants and your enemy zombies. After completing adventure mode, you'll be able to play some of the many mini-games and puzzle missions that provide a real sense of depth and variety to the game. Simply put, Plants Vs. Zombies stands out not only because of its quirky humor and unique art, but also because the game is so replayable. Unfortunately, the iPhone version lacks some of the 20 mini-games, 20 puzzle missions, and 11 survival modes that were offered in the full Mac version. While many of the bonus games are unlockable, the omission of the stages that let you play as a zombie is unfortunate.

On my iPhone 3G, there were some technical difficulties. I experienced significant frame rate drops when there were several dozen plants firing at the same time as a large wave of zombies approached. It wasn’t enough to stop or crash the game, but I did notice the rate of fire of my pea pods dropped significantly during those times. I liked the new plant menu on the side of the screen (instead of on top in the original) but things feel a bit crunched with the money counter at the bottom usually blocking your last row of plants. The touch screen controls on the whole, however, were quite responsive and intuitively designed.

I was also happy to see Crazy Dave again. Like an insane uncle you only see on the holidays, it was good to see him again. Crazy Dave is the game’s guide, shopkeeper, and constant comic relief. He’ll introduce you to the different modes of the game, sell you new seeds, and spout gibberish. Crazy Dave is also one of the weirdest characters I’ve seen in a game, at times extremely helpful and other times channeling Hunter S. Thompson a la Fear and Loathing in Las Vegas.

The lifeblood of your plant army is smiling sunflowers that produce precious sunshine. You can use sunshine to purchase plants that will defend your five or six lanes of lawn or roof from the invading zombies. Just as each zombie has its own skill, each plant has its own ability. Walnuts serve as walls (that’s a pun, get it?), snow peas shoot icy peas, peppers explode, and cacti fire spikes.

As a tower defense strategy game, Plants vs. Zombies is remarkably deep. There are over 20 types of seeds and zombies, so the game goes far beyond the typical “rock-paper-scissors” formula. Some plants will be nearly universally useful, while others will be very helpful against some very deadly specialty zombies. For example, when playing throughout the backyard missions (where you’ll have to deploy lily pads or other water-based plants to fend off inflatable-duck-wearing zombies) I had to be vigilant against mining zombies that could burrow under my lines and attack me from my flank. I eventually deployed twin direction pea pods and potato mines—the combination helped stave back the horde and I lived for another day.

This addictive game has six main levels in adventure mode, split into a number of missions per level. You’ll defend your front yard, backyard and roof in both nighttime and daytime settings, using different plants for each mission. Each environment has its own advantages and challenges, but by the end you’ll be wishing they were more varied, exotic, and bigger.

I laughed several times out loud during my many hours playing this game. When you beat a level in adventure mode, you’ll often obtain a note from the zombies. They’ll ask, in poorly spelled handwriting, to either leave your home unguarded or to surrender or some other poorly conceived plan to get to you. The “help” menu in the game tells you to “just sit there and don’t do anything. You win the game when the Zombies get to your houze.”

The tongue-in-cheek mini-games and varied modes provide some depth and diversity to Plants vs. Zombies that separate the title from its peers. Frankly, Plants vs. Zombies biggest flaw is likely the limits of its genre—tower defense—and the mini-games help break up the monotony inherent in such games. With amazing character concepts, clever humor, and an overall attention to detail not seen in other tower defense games, Plants vs. Zombies is one of a kind.

[Chris Holt is a Macworld associate editor.]