There have been many rivalries through history; cat versus dog, pirate versus ninja and the equally fierce but seldom reported battle between plants and zombies.

The Nintendo DS is the latest arena in which these age old foes lock thorns and fetid flesh, yet Plants vs. Zombies still manages to produce an addictive formula that requires a surprising amount of strategy.

Not in my back yard

The aim of the game is to prevent waves of bloodthirsty zombies from entering your house by strategically placing various plants in their way. This may sound simple enough, but a thoughtful approach is necessary to avoid having your brains devoured by the walking dead.

A vast selection of horticultural delights are available to aid your struggle, ranging from attacking options such as pea shooters, which issue damage to the zombies, to defensive plants such as walnuts which just slow them down. Of course, these are the standard building blocks of the tower defence genre in plant form.

And although the scenario is far fetched, the game doesn't ignore the concept of photosynthesis as each plant requires varying amounts of sunlight to grow. This can be obtained from the sun (naturally) or from sunflowers. The simple and intuitive controls make good use of the DS’s touchscreen as plants are simply dragged from the toolbar at the top of the screen to their desired position while sunlight is collected with a simple tap of the stylus.

Undying appeal

Adventure mode is the main course of the game and is a meaty 50 level campaign divided into five game worlds. To begin with, you only have a meagre selection of plants to choose from, but new plants are unlocked as the game progresses. Elements such as night time and water are introduced which add a further tactical dimension as certain types of plant can only be used in certain conditions, while night levels offer no natural sunlight.

As the player advances through the levels, the zombie onslaughts become more frequent and frantic and new types of enemies become a factor. These range from pole vaulting zombies which can leap over your walnuts to disco zombies who summon back up dancers from the dead. New concepts are introduced gradually, giving players ample time to get used to them. If you’re still having trouble, items and upgrades can be purchased from Crazy Dave by using coins which are accumulated throughout the levels.

Various challenges such as mini-games, including four that are exclusive to the DS, are unlocked during the adventure mode while gamesharing and multiplayer support is also included. This enables you and a friend to compete as either plants or zombies, while the mini-games include a version of baseball, a side-scrolling shooter plus more puzzley options. In addition the Survival mode tests your endurance, but perhaps the most intriguing mode is Zen Garden, which allows players to cultivate their plants in a secure environment and is a peaceful proposition when compared to the other zombie-filled modes. These extend the lifespan while coins earned in these challenges can be used in Crazy Dave’s Shop.

Screaming may save you

Still, the game is not without its failings and although the touchscreen controls are implemented efficiently, things do come unstuck slightly during attempts to utilise other aspects of the DS’s hardware. The upper screen is merely decorative aside from a metre showing you the status of the current onslaught, while on occasion the game requires you to shout into the microphone to stop your plants from wilting, although mercifully this is a rare occurrence.

Another criticism is that the variety of plants often overcomplicates matters as the game attempts to increase the number of tactical options by introducing more plants. For most players, some of them are rarely used. Often a crude explosion from a cherry bomb is more effective than a subtle use of garlic to make the zombies change lanes.

These minor shortcomings aren't significant enough to detract from what is a very good portable package however. Plants vs. Zombies is able to differentiate itself from the rest of the crowd by creating an effective blend of tower defence and strategy that simply oozes with charm.