Touchgrind BMX

Ironically enough, Touchgrind BMX doesn't actually feature any grinding. Your bike has no shiny chrome pegs, and the handful of skate parks on offer are conspicuously devoid of rails and ledges.

The game doesn't feature flatland tricks, either, nor manuals, heroic seat grabs, or deadly handlebar headstands. Considering the types of tricks you actually have up your sleeve, Touchflip BMX would be a far more suitable name.

In this gorgeous multi-touch semi-sequel to skateboard sim Touchgrind, you guide a BMX around a skatepark (or Incan ruin or skyscraper rooftop - the usual haunts) and launch it off various ramps, bumps, and leaps.

While in the air you can rotate the handlebars, whip the tail around, spin the bike like a roman candle or do audacious, screen-spinning somersaults.

Your spooky ghost bike doesn't have an extremely rad dude manning the handlebars. Instead, your pinkies do the deed - if you're right-handed you'll plop your index finger on the seat and your middle finger on the handlebars. This lets you peddle and steer about, and different types of flicks and gestures pull off the game's meagre selection of tricks.

If you want to score big on Touchgrind BMX, you'll have to leave your petty belief in things like gravity and physics at the starting line.

According to developer Illusion Labs, and contrary to the observations of Isaac Newton, you can trundle off a small jump and do two front flips, a free spin of your bike, and a handle bar whip without ending up in Accident & Emergency.

But you'll also need to retain a modicum of restraint. Achieving anything close to a high score requires you to keep a score multiplier ticking over, and any wipe-out will reset the counter to zero.

BMX has a tasty mix of risk and reward, where every gravity-defying manoeuvre could net you a new high score, or ruin your entire run.

It would of course be sensible to assume that a steady hand, an encyclopedic knowledge of the game's tricks, and some patience is all you need to keep your bike upright and your multiplier ticking over. Unfortunately, this latest Touchgrind game doesn't make it that easy for you.

Take the camera, which nauseatingly follows your bike around during a front flip and makes it near impossible to line up your landing. Or the way your massive fingers obscure much of the action, often concealing ramps and making upcoming obstacles invisible.

Or when you go slightly off the predetermined course and it warps you back to the track - mid trick. Or when the game simply doesn't register a flick, or reads your lightning fast pinky slash as a meandering stroke, and turns a tailwhip into a useless tailrevolution.

More often than not, Touchgrind BMX results in maddening, blood-boiling, hair-wrenching, seething frustration that makes you want to punch a wall and invent new curse words.

If you plan to get anywhere near a shiny gold medal, you'll have to go through more than a handful of badly failed attempts.

But when it works - when you pull off a perfect run of smooth tailwhips and amazing backflips, accompanied by a high score multiplier and a shiny gold medal at the end - Touchgrind BMX is, for all its frustrations, extremely enjoyable.

When they're not defying the principles of physics the BMXs handle like real bikes, and pulling off the toughest tricks at the end of a good run is extremely rewarding.

Unlike its skateboarding predecessor, this pseudo sequel has some proper challenges to beat. Things like 'Do a 360 spin from the ventilation shaft' or 'Get at least 50,000 points in one jump'. As you unlock new bikes, paint colours, and levels for beating challenges, it certainly gives you something to aim for and do.

Still, a less linear Freestyle mode would be nice. BMX is practically on a conveyor belt, as you're tugged around a hemmed-in course like there's a rope anchored to your handlebars. The only movement you need to do is to screech to a halt and slowly manoeuvre your bike about 90 degrees to hit an awkwardly angled ramp.

A nifty feature worth mentioning is that a video of every run is automatically recorded, from a variety of angles, and archived for later viewing. You can then save them into your iPhone's stash of videos and upload them to YouTube if you feel like showing off.

Touchgrind BMX precariously straddles the line between frustrating and fun, like a BMX grinding a thin rail over a pool of water. If Touchgrind featured grinding, that is.

The game has an epically steep learning curve that pays off when you reach the summit, but whether you can stomach the climb depends on how many times you can see your bike turned into mangled metal by an awkward camera angle or failed flip before hitting the home button.