Critical Wave

Few things are more irritating than discovering your PC has been infected with a virus.

It's an annoyance of which most Mac owners are blissfully unaware, yet you don't need to have experienced the crippling effects of a virus to want to obliterate them in Critical Wave.

The game is one of survival. Enemy waves are never-ending, consisting of various geometric shapes to be destroyed with a flick of the fingers. Boss battles conjure up shapely conglomerates that reward special power-ups when killed.

Destroying enemies fills a bar at the top of the screen, which indicates when Infecto appears. This transcendent virus only descends to attack once enough lesser viruses have fallen. Ever evolving, he gets bigger and deadlier each time you fight him. His amusing taunts at the beginning of each round are great.

The whole thing is a visual treat, with neon lasers, particle effects, colourful lighting, and an extremely busy screen.

There are plenty of subtle touches, like the fact that the game automatically pauses when you lift your fingers from the screen. Level borders can be used to escape border patrols; there are mines that infect sectors and make them deadly to fly over; and upgrade points enable you to level up your weaponry as you progress.

Unfortunately, the narrow field of vision and fact that your thumbs obscure most of the lower screen mean that you're not always fully aware of your surroundings. You can use multi-touch to zoom out, but only to observe.

That's fine in a slow-paced game, but disastrous in a shooter - being killed by a bullet that flew under your thumb is frustrating. Despite the technological threat, it’s often biology that is your downfall.

Despite these problems, Critical Wave is a genuinely good game with great flair. Whilst not quite in the same league as the games it affectionately emulates, it will certainly make Mac users wish they had to deal with more viruses.