Beetle Breaker is basically Angry Birds: Beetle Edition, but instead of hitting pigs with birds it's all about slingshotting - presumably TNT-spliced - bugs at lumps of wood and other materials. Why the bugs are suicidal is never explained.

You have to destroy a lump of misshapen wood in the centre of the screen, killing the smallest number of beetles possible - it's all scored on a three-star system, based on efficiency.

After introducing these basics, the mechanics get more complicated.

First comes the introduction of new types of goggle-eyed beetles. Some split into two with a tap, exploding on impact. Some fly over the target instead, planting charges across it as you tap the screen. Others plant clusters of bombs which link together when in close proximity, only to be detonated by another beetle, causing a chain reaction.

Inevitably, sometimes cluster bombs miss. This usually sees the stray bomb bouncing from one side of the screen to the other for what feels like eternity, before eventually falling to the bottom. Only then will the game let you proceed. It's maddening.

Infestation

These beetle variants add a tactical layer to a simple game, forcing you to plan ahead. If you don't manage to finish with the bugs available, the game gives you the option to spin a wheel of fortune - a chance of winning a bonus beetle to destroy the last piece of wood. You get one of these free a day - otherwise you gotta pay.

All of the levels can be completed without using the wheel, though some of them are fiendishly difficult - especially once the target starts revolving. Sometimes it's obscured by indestructible brick walls, and sometimes it's protected inside a mysteriously explosion-proof bubble with a single vulnerable spot.

There are also perks you can buy with gold that's awarded after you complete a level. Although hardly noticeable at first - offering small percentage increases to explosive powers, for example - these add another layer of strategy to this physics-puzzler.

There's something about slingshotting bugs at wood that just feels right. The satisfaction that comes from setting up a perfect chain reaction justifies the download along. Apart from a couple of issues that may bug (sorry) you, Beetle Breaker is a brilliant, characterful little casual game.