Here's a rather snazzy sci-fi FPS that seems to have been conceived as a portable, low-cost take on Halo.

Press-ganged back into miltary service by some gung-ho thugs, you are faceless jock Kal Wardin, and your mission is to investigate some nefarious alien goings-on aboard a derelict space station. Actually, investigation might be too lofty a description: the gameplay principally involves following some clearly sign-posted paths, shooting things with ever-bigger guns, and hitting the occasional switch.

N.O.V.A. is not going to win any prizes for depth: run a bit, shoot a bit, collect some ammo, run and shoot some more. However what it lacks in complexity it makes up for in simple pick-up-and-play fun.

Serious gamers might find it a bit too easy, but even they ought to be impressed by the top-notch graphics, atmospheric design and decent, responsive controls (by the iPhone's admittedly low standards).

Less impressive is the plot; you'll need super-human patience to not skip the many cut scenes, and if you do skip you'll not be missing much. Also, it could do with a bit more variety in weapons and adversaries, and no effort seems to have been made to imbue the supporting characters with any, well, character.

However, flaws aside, this is a hugely enjoyable knuckle-headed romp, and at the moment there is no better FPS for the iPhone.