The tower defense genre has become one of the most popular and densely overcrowded game types in the casual sphere, its simplified battle strategy recipe attracting more desperate reinventions than Katie Price's PR strategy.
But few variations on the theme have proved as stylish and entertaining as Plants vs Zombies, another perfectly balanced, helplessly addictive super treat from the indefatigable Popcap stable. Released on Mac and PC last year to an enthusiastic critical reception, it has now shuffled onto the iPhone and iPod where it's set to attract a new legion of slavish followers.
Your job here is simple. There's been a zombie apocalypse (yes, another one), and you must protect your home from the incoming undead hordes by nurturing various killer plants in your garden. Peashooters fire projectiles at your slavering enemies, while cherry bushes blow them up and walnuts (or 'wall nuts' as they're known here) stop them in their tracks for several seconds. At first, only a few seed types are available to you, but each time you complete a stage, you unlock a new plant weapon.
The catch is, just as you need to mine for resources in an RTS in order to build units, here you must top up on sunlight to grow each new vegetable-based assassin. This involves catching the sunlight icons that fall from the top of the screen, or planting sunflowers, which generate their own sunlight: a decent patch of these is necessary to really start building a strong leafy armoury.
However, tower defense games are all about balance and PvZ is no exception. For a start, you can only select six seed types on each level; do you go for the little ones that grow quickly but inflict less damage, or stock up on the big guns like the chomper, which eats zombies whole, but takes longer to germinate? Added to this is the array of different zombies – some wear helmets (or rather tin buckets and traffic cones) to protect them from your pea bullets, while others sport special skills like the ability to pole-vault over your emplacements. They'll all eat your plants when they get close enough, so the battlefield is a constant tug-of-war between your green fingers and their gaping, insatiable jaws.
The key to success is managing your weapon lines, ensuring you have a well-protected patch of sunflowers to generate light, and also an array of different plants in each line (the zombies kindly attack in columns from the far end of your garden) to cope with any type of enemy that wanders by. Fortunately, the touch controls are perfectly implemented allowing you to tap on a seed type from your menu and just jab where you want it to go. It's actually more intuitive than the Mac/PC mouse iteration and allows for really rapid engagement – extremely useful for the later more chaotic levels.
Added challenges come later when nighttime falls, drastically reducing your sunlight production; after that, you move to different locations around your house, each bringing new difficulties. But then, it's also possible to pick up coins throughout the game which allow you to buy various upgrades – again, it's all about balance and Popcap has got the fulcrum absolutely right here, between constantly evolving threats, and a gradually boosted armoury.
The game is beautifully presented too, with detailed and amusing animations (especially the OAP zombie who hobbles on reading a newspaper only to become enraged when your projectiles destroy his reading material), and a suitably eccentric soundtrack. And of course, the overriding concept itself, marrying the approachable gardening feel of, say, Farmville, with cartoon zombie horror, is wonderfully realised.
So predictably, Popcap has done it again. Following the wonderful iPhone translations of Bejeweled and Peggle, Plants vs Zombies is masterful stuff, loaded with charm and an utter joy to interact with via the iPhone touchscreen. For those who feel they are irreversibly exhausted with tower defense games, the sleek presentation here may just spark some life back into the genre. Everyone else should consider it an essential purchase – if only to hear the zombies drone 'brains!' as they march toward your front door.
