GAME OF THE WEEK:15 cert, Digital Reality/ Grasshopper/Microsoft, Xbox Live ****

“Your gift, like rage, is meaningless without power,” says an ominous voiceover in this super-serious shooter. Yes, while it may play and look like a classic 1990s shoot- ’em-up, Sine Mora is coated

in a backstory involving a rebellion, revenge and war crimes. This story is simply presented before every level as text on a sombre black screen, but it is engaging and intelligent. If nothing else, Sine Mora has conviction.

But Sine Mora is much more than a lecture on ethics. At its heart, it’s a side- scrolling retro shooter. Scrolling smoothly (usually) from left to right, you negotiate various aircraft through hostile territory.

It’s tricky. As well as avoiding and fighting an army of enemy vehicles, time works against you. Fail to complete a stage within the time limit, and you simply explode.

Thankfully, you have the (limited) ability to slow down the action, which gives some welcome breathing space, and reminded me of when similar games on the C64 used temporarily to freeze. And, like the best shooters, it becomes strangely graceful, as you learn to glide through the swirling explosions and missiles.

Graphically, Sine Mora shows what can be done with an old, mostly forgotten genre. The vehicle design is incredible – small steampunk planes swirl around gigantic, imposing machines. One of the levels involves taking down a giant mechanical spider; another requires that you destroy (piece-by-piece) a futuristic wrecking-ball machine. There’s a gratifying variety of explosions.

This is not for the faint- hearted or unco-ordinated, though: difficulty levels in Arcade mode range from “Hard” to “Insane”.