App of the Day: Virus Wars

In the hugely competitive world of mobile games, which have to work that little bit extra hard to capture our attention while they're squeezed onto platforms bulging with new releases and valued at throwaway prices, Virus Wars is yet another worthy and addictive distraction from endless work emails, Twitter notifications and text messages.

Gameplay-wise it's similar to Dots and Boxes, an ancient two-person pen-and-paper game I used to play on school coach journeys before Game Boys were invented [surely you weren't alive then? -Ed]. Virus Wars greatly improves on the formula, however.

The game tasks two players (likely you versus the remarkably savvy AI) with marking territory across a gridded page of squares, starting at opposite corners and moving one space at a time. Each space you move through gets a crayoned cross in your colour (the mark of your 'virus') and from each of these crossed squares you can spread your territory to further infect the playing surface in any direction.

When you meet a space already crossed by your opponent you can scribble over the top, claiming the box as your own for the rest of the game. This creates a wall that the other player then has to work around, although they may still slip past diagonally.

Like the marvellous Drop7, writing the concept down makes it sound incredibly dull, but the joy of Virus Wars comes from initially being fairly rubbish at quite a straightforward concept before slowly learning the true tactics of the thing. Eventually you get to the point where you have a set of strategies to hand for almost any situation the tricksy AI might throw at you. This is when Virus Wars really starts to feel rewarding.

Knowing when to reinforce your squares, when to branch your path of attack or when to sacrifice spaces to be taken, is vital. Captured 'wall' spaces count as your own, but fall dormant when cut off from your crossed-out spaces, adding another level of complexity to the proceedings. Gameplay ends when your opponent has no crossed spaces to move from, or you completely encircle him with walls.

Virus Wars boasts three AI levels and a decent tutorial mode that gives new players just enough information to learn the basics. You can raise the difficulty further by increasing the size of the playing space, right the way up to monster-size levels that require plenty of scrolling navigate.

Multiplayer options exist for online play with Game Center friends, or Bluetooth matches with other iPhone gamers in the same room. Alternatively you can crowd four people around one phone for truly local play, perfect for coach journeys. With its simple concept and complex depths, Virus Wars is ultimately as infectious as its name suggests.