Numba (iPhone)

You'd be surprised how much a touchscreen can improve a regular puzzle game. Well, you might not surprised if you've been playing some of the mobile games that have been ported to iPhone.

Any game on mobile that involves laboriously moving around a grid benefits from it - and of course, it's not just on iPhone, but on any touchscreen handset. Swiping your finger or thumb along a row of gems or jabbing at a button is so much more satisfying.

Numba certainly benefits. On mobile, it was a good number-based puzzler, but its format lends itself perfectly to the touchscreen treatment. The actual game is largely unchanged, but its graphics have been boosted to suit the larger screen too.

Assuming you're new to the game though, here's how it works: you're presented with a grid of numbers between 1 and 9, and your job is to create sequences by dragging your digit through adjacent tiles. A sequence has to be at least three numbers long, but its makeup is flexible. It might be three 1s for example, or a 1-2-3-4 sequence, or an incremental series (1-5-9).

Get a sequence, and the tiles disappear, with more dropping down from above. Strategy, then, is a case of finding these sequences, but also lining up longer ones by keeping an eye on the whole screen.

There are three ways to play Numba on iPhone. Classic mode sees you competing against the clock on each level, while Timeless mode removes the time limit to present a more relaxed puzzling experience. There's also a Puzzle mode consisting of a slate of tricky stages.

If it was just creating sequences of numbers, the game would soon get boring. Happily, there are special tiles to deal with. Some change number every turn, some are frozen, some have time limits, and others have score bonuses. Learning to deal with these is how you boost your score and where the real challenge lies.

You can also collect Jumble bonuses, which allow you to shake the iPhone to jumble up the screen and (hopefully) reveal new sequences. It's another example of how the iPhone accelerometer can be used in subtle but impressive ways in this kind of puzzle game.

Meanwhile, Puzzle mode sees you trying to solve 78 specific puzzle layouts, again without a time limit. The three modes offer a decent amount of variety, although we found we preferred the less-stressful experience of Timeless mode as a time-killer.

Numba doesn't really tax the iPhone's hardware, given that it's a screenful of numbers. However, it does look bright and colourful, with the numbers the right size to ensure sausage-fingered gamers don't jab the wrong ones on a regular basis. The sound doesn't stand out, but it complements the gameplay well. But given its GBP 3.99 price point, and the improvements over the mobile version, it's a good deal.

All in all, it's a pretty addictive package, and one of the dark horses of the App Store. It might not be as high-profile as the likes of Super Monkey Ball and Crash Bandicoot Nitro Kart, but make no mistake, this is one of the more impressive iPhone puzzlers available.