Quadblast

Quadblast plays like Geometry Wars, if the twin-stick classic had been put together by a minimalist with a set square and a steely devotion to precision movement.

You're dropped into a claustrophobic single-screen arena, and need to fend off endless attacks by black shapes that bounce off the walls at perfect 45-degree angles.

Fortunately your own movements aren't so restricted, with smart tilt controls allowing you to deftly weave your white ship through your attackers.

It's not all about heroically squeezing through gaps and eliciting digital cheers of 'near miss' from the game though. You're also armed.

Swipe in one of four directions and your disc emits a white beam of doom, obliterating everything in its path.

Your weapon is strictly limited to vertical and horizontal blasts. The effect when combined with Quadblast's free-form movement is a little like rubbing your tummy while patting your head.

But this is far from the meanest of the shooter-in-a-shoebox sub-genre, and gives you plenty of time to adjust to its unfamiliar controls.

The black discs sportingly fade in to the arena, and have a little triangular nubbin that telegraphs the direction they plan to set off in. Rather less sportingly, you can blow them up while they're in this state.

The final piece of the puzzle is the glowing orbs eradicated targets leave behind, which you can scoop up to increase your multiplier.

These orbs feel like they're designed to force you into the arena. Without them the best tactic appears to be lurking in the bottom-left corner, firing up and right as necessary.

It's a pity the multiplier doesn't deplete and force you to take risks to nab more orbs, and it means Quadblast is sometimes a little too easy.

That feeling does disappear as you spend more time with the game. One of the achievements tasks you with remaining within a small circle in the centre of the screen for 50 seconds without dying.

It's a decidedly hairy and exciting experience, and entertaining enough that it deserved its own mode.

There's very little variety in the game as a whole, beyond a few different attack waves here and there, and a gradual speeding-up as you polish off the levels.

You can upgrade your ship, buying a wider beam, powering up your orb magnet, or adding shields to survive collisions, but none of the add-ons adds much to the experience.

It's a pity, because something more would propel Quadblast into that crack squad of must-have iOS arena shooters.

The game looks good, has responsive controls, and fantastic tilt calibration. It plays well too, at least on iPhone - it's a tad unwieldy on a full-size iPad. The problem is that lack of progression.

For free, it's nonetheless a no-brainer for fans of abstract shooty/avoidy games. Just don't expect it to become your iOS shooter of choice.