Razor Salvation THD

If you run through a checklist of what makes a great mobile shooter, Razor Salvation THD has it all.

But for all its plus points - like waves of invading aliens to mow down, and an arsenal of devastating weaponry to do to the mowing with - this Tegra 3-exclusive Android port of the mediocre iOS original manages to veer dangerously into dull territory with every twist of your dropship's turret.

Most of the blame falls on the sluggish gunplay, drab visuals (apparently the textures have been tweaked a tad), and fiddly aiming, but the game's attempt to extend the life of its measly four levels by making you replay them countless times to upgrade your equipment also does its bit to ruin your fun.

Following an alien invasion by the Xenos, your mission is to fend off hordes of crudely animated enemies from the relatively safe confines of a dropship long enough for civilian stragglers to hop aboard and be flown to safety.

You can't win - you just earn higher scores by hanging on for longer and longer against endless waves of increasingly persistent enemies, from standard rifle-wielding grunts to shuffling zombies and insectoids straight out of Starship Troopers.

Your cockpit revolves 360 degrees to let you take down foes from all sides using a rather impressive stock of weaponry, ranging from a standard mini-gun to a rocket launcher and a devastating - one zap kill - railgun.

Enemies are obligingly slow in getting to you at first, which is a blessing as the turret controls feel sloth-like and gloopy. Notching up the sensitivity helps, but at the expense of accuracy, as shooting then becomes jittery.

Plugging a game controller helps a fair amount, but the promised support for the Xbox 360 pad didn't work with my Nexus 7 until every control was painstakingly remapped.

There's also, gratingly, a major focus on steadily upgrading each weapon using cash earned by grinding through the same rather bland-looking levels. Until you've really powered everything up, the only way to keep fighting is to leap between weapons whenever the dreaded 'reloading' bar appears.

With no part of the gameplay proving particularly engrossing, not to mention the lacklustre presentation (including a jarring Nvidia logo on almost every surface), it's hard to recommend Razor Salvation THD to anyone but the most die-hard alien shooter fan.