Naught was one of the better silhouette platformer-puzzlers to appear on the App Store in 2011. In it, you took control of a bipedal cat, whom you had to slide around cavernous levels by tilting your iPhone or iPad. It was tricky, but once you get a handle on the angles it was a pretty good time.

Now, the spelunking feline has returned in a new game featuring spruced up animations, faster levels, and some seriously testing bosses. Most of these changes make Naught 2 a prettier, more exciting experience. Be warned, however: the game isn't past throwing some seriously off-putting difficulty spikes your way.

As before, you take control over the environment rather than the protagonist. If you choose to use the accelerometer, you can send your black cat sliding down walls and free-falling through gaps by tilting and rotating your device. Though it's a little awkward to turn your iPad a full 360 degrees - especially if you're wearing headphones - the game responds well, smoothly switching the centre of gravity to reflect the unit's orientation.

The touch screen controls work great, too, though we found it trickier to quickly reverse the cat's direction using this technique.

Once you've mastered the controls, you'll want to explore the multi-chambered levels to find blue crystals (which serve as extra lives) and black diamonds (which replace the 3-star system). You have be careful, though, as later levels play host to carnivorous plants, brambles, and vines, which can instantly snuff out the life of our courageous kitty.

To compensate for the pacier gameplay in this sequel, you now view the action from greater distance, allowing you to see more of the map. It's important you spot enemies as soon as possible, as you'll often have to fight momentum when making course corrections - something which can prove impossible if left too late.

Discovering hidden pathways and weaving through rotating islands is exhilarating, and the splashes of colour stand out beautifully against the gloom.

However, while you are able to gradually ascend the steady difficult curve of the standard levels, the game throws a brick wall in your face with the first boss battle. Dodging the creature's rapidly spawning tentacles is incredibly tough using either control system. You'll likely use up all the continues you've gathered on previous level, and more besides, and the whole fight feels a bit cheap.

However, in every other way, Naught 2 is a step up on its predecessor. It's definitely one of the better silhouette platformers around. Provided you can grit your teeth through the bosses, you should find Naught 2 a shadowy delight.