Metal Gear Solid Touch

That's about it, although Kojima Productions has thrown in a handful of twists. There are a few friendly hostages that will deplete your health if you shoot them. If the enemy's at long range, you'll need to zoom in with a two-fingered pinch (just as you would on a webpage in Safari) which switches to Snake's wavering sniper rifle sights. Shooting certain pickups grants you health, "stealth" (actually temporary invincibility), or a rocket launcher to help take down a Gekko mech, a chopper or a boss. (The bosses are the imposing Beauty and the Beast squad of psychotic cyber-ladies, more or less exactly as you found them in MGS4.)

All of it works to unfussy, fine-tuned perfection. Working your way through harder levels - there's a not unwelcome but rather sudden difficulty hike halfway through - is a pleasing mix of reaction-test, rhythm-play and spatial awareness, as you watch the timers for a window to re-sight the crosshair to the other side of the screen, zoom in on a distant pickup, or pick off a group of enemies. The patterns vary on replays too, just to keep you on your toes.

Unlike a light-gun game, aiming takes appreciable time and must be planned for, but the touch interface means it still feels believable and tactile, and less alienating than manipulating a cursor with a stick. It's just a little like what we imagine being in an actual gunfight to be like. The more basic pattern-recognition of the boss fights is less successful, though.

It's also beautifully presented, as you'd expect from Kojima Productions. Everything's been done in 2D sprites and flat backgrounds with a loose, hand-painted look. Some gentle depth-of-field blur and impressively gritty screen overlays, and a reverential care for translating Guns of the Patriots' moody palette, make this one of the best-looking iPhone games. It sounds great too, with wholesale lifts from the PS3 game's terrific score. Doling out the plot in chunks of plain text over a bit of art seems a bit lazy though, and it's 100 per cent spoiler for anyone who hasn't played MGS4.

Metal Gear Solid Touch is a slight offering, although it's none too pricey. Completing the twelve levels unlocks a Survival mode - your health and timer last from level to level - while improving your ranking on levels in the main mode earns Drebin points, which can be exchanged with the black marketeer for pin-ups of the sexpot cast. But as slick and punchy as the game is, it just doesn't have the mechanical depth to give it reply value as a score-attack game. You won't feel that compelled to return to it after an hour or two, and there are better-value propositions all over the App Store.