App of the Day: Gridrunner

Endless upgrades, star ratings, in-app purchases and bags of customisation features. It's amazing how cluttered the average mobile game is with all sorts of bumpf. Gridrunner has absolutely none of this, and the closest it gets to a tutorial is an attract mode. It's not old-school. It's OLD-SCHOOL, with no time for fuss.

Gridrunner was originally programmed for the Vic-20, and this iOS version includes newly spiffed-up versions of both that and the Commodore 64 version. Despite the old-school visuals these are a great bonus, accessed by turning your iDevice to landscape view. But the main event in Gridrunner iOS is 'pure' mode, where Llamasoft - Jeff Minter - transplants the old Gridrunner elements into the portrait view of classic arcade shooters.

Like all of Minter's games, Gridrunner requires a brief period of acclimatisation - working out the bloops and blops, figuring out what to shoot, what to grab, what to look out for. It's a smooth learning curve thanks to the gorgeously deft control scheme, which has the ship autofiring while you control its movements with a single digit.

Your finger can be placed anywhere on the screen, and the speed and accuracy of its movements are captured exactly in the ship's movements, a gooey inertia during slight adjustments or a whizzing dash away from a war zone. The game also features iCade support, but that's just the cherry on the cake.

By the time you've nailed the controls, you've also learned what to look for. Gridrunner's a strange mix of twitch shooter and puzzler where your constant blasting can be made exponentially more efficient by recognising and exploiting the ever-shifting background terrain.

Enemies move down the grid gradually at first, in Centipede-like formations that break apart and leave debris as they're shot to pieces. This debris can then be used to funnel enemies into concentrated fire, catching long lines of them, Galaga-style, but after a certain time the debris into missiles. This can also be juggled for big points, but it's a hard trick to pull off when things get frantic.

The first few grids are easy, but soon you start hitting the crazy zone - the screen's jammed with deadly pixels, the ship desperately darting left and right, and the sweet sweet screen-clearing power-ups become your sole focus. These new power-ups ratchet your ship's firepower for a few brief, blaring seconds and let you mow down almost everything on the grid if used correctly. It's entirely possible to bounce from one into another, a concerted bullet hell that wipes entire levels clean in one beautiful adrenalin-fuelled burst.

This isn't just a great shooter, it's a thrilling one. Half the time you don't even see what destroyed the ship, the screen so swarmed with nasties that your finger's long since taken on a life of its own, somehow threading a needle between shrapnel and laser beams before they even register. Gridrunner's a blast, and the best shooter on iOS.