Whether you're sat on the bus on the way to work or in comfort in your own living room, nothing beats thwarting an army in the palm of your hands.

Luckily, if you own Sony's latest handheld you can do just that in Grasshopper Manufacture and Digital Reality's Sine Mora.

You'll want Mora

As Sine Mora is a Grasshopper Manufacture game, the quirky Japanese game designer Suda 51 has naturally had a rather large hand in its creation.

Because of this, it's a wonderful mix of pure nonsense and tight gameplay. It might be some incredibly well thought-out and beautiful nonsense, but it's still convoluted and winding in structure.

You take up the controls of a range of fighter pilots as they set out on a mission to thwart the plans of a gargantuan and ever-expanding empire - known simply as the Empire.

However, it's not as simple as it first seems, as Sine Mora's story is actually two tales intertwined.

One thread details the struggle of a race nearing extinction as it exacts its revenge on the Empire. The other recounts the vengeful desires of a father whose lost his son at the Empire's hands.

It's nigh-on impossible to really tell what's going on - even with the inclusion of text-based stage introductions and fully narrated levels. But, quite honestly, it really doesn't matter as you'll probably only play the story once, choosing to hit the far more challenging Arcade mode when you fancy playing through the stages again.

Bullet heaven

Shmup aficionados will be pleased to know that Sine Mora doesn't ever disappoint when it comes to gameplay - even on the smaller screen.

It works largely as you'd expect for a bullet-hell title: lots of enemies, lots of bullets, and lots of tight spaces to navigate through while making sure you survive.

Sine Mora is a little different, though, as it gives you the ability to bend time to dodge faster and lets you stack upgrades that spill forth from your ship when hit.

Interestingly, it also measures your ship's health in the form of time. Shooting enemies increases your time for each section of a level, while taking a hit subtracts a few moments. It's an ingenious way of increasing the pressure while giving beginners a chance.

Playing through on the story's Normal or Challenging modes still provides the uninitiated with a dastardly curve to climb. Venturing into Arcade mode presents you with an even tougher challenge as you can only pick from two even harder modes to play though on.

Sine Mora definitely isn't for those with soft skin - it'll pound you with bullets from all directions until you're left buffeted and bruised. But if you're made of the right stuff you shouldn't miss out on this polished and innovative take on the bullet-hell genre.