It's tough to translate a tactile sport to the touchscreen, especially one in which a slight smidgen could mean the difference between a gnarly loop and an epic fall.

The trial bike game Xtreme Wheels has the visual strength and, perhaps, even the attitude to avoid the latter perilous outcome, even if it does possess some occasional performance slowdown.

On the road again

Xtreme Wheels takes its cue from the classic Tony Hawk games - those brilliant titles that finally managed to capture the underground skater culture in a video game format.

Here, though, the action unfolds on a motorbike, where instead of an open arena, we're working towards narrow, bite-sized, focused challenges - perfect for this mobile environment. It's not about exploring or unlocking stuff, but producing the best run.

Each of the five locations - the Warehouse, Factory, Sawmill, Foundry, and Scrapyard - test your skill, speed, and crash-avoidance chops.

The 25 levels feature plenty of ramps and traps, but the strength of Xtreme Wheels lies in the room it gives you to have fun.

For example, at various points, you'll come across a ramp that can simply be hopped over - well, the average game would expect you to do that. With Xtreme Wheels, however, the game trains you to see it differently. Is it high enough to perform a flip? What about a backwards one?

Thankfully, the controls are straightforward: there are buttons to lean back, lean forward, accelerate, and brake. The setup was easy to pick up, but, as you can imagine, it was tough to master along the varied areas.

A pretty picture

The graphics aren't just big: they're orca big. The biker himself takes up a third of the touchscreen, while dense and detailed backgrounds full of rusty metal and well-worn wooden structures whizz by.

You'd be hard pressed to find a more graphically detailed sports title, particularly when you see it on iPad. The crash sequences, of which you will witness a lot, are both brutal and beautiful, with your biker's neck violently snapping and blood shooting from his arteries.

The visuals come at a price, though, since the 3D graphics engine appears to tax the iPad. The controls are fine, but there is a certain sluggishness even on the iPad 2 - the most powerful iOS device on the market.

It isn't enough to hurt gameplay per se, but it definitely means the game moves and feels slower than the developer intended it to. Ironically, the iPhone version seems a little smoother, perhaps because its smaller screen makes it easier for the rendering engine to update.

Fancy footwork

In the end, Xtreme Wheels proves pretty darn playable. The key to its success is the simplicity of the controls: instead of trying to create something as complicated as the console sports experience, Xtreme Wheels presents you with a palette of options for getting creative within a small environment.

And the later levels certainly ramp up the creativity stakes, bringing in quad-level ramps, sensitive explosives, and neck-snapping obstacles.

Xtreme Wheels isn't as smooth as we would like it to be, but the end result is interesting and varied enough to recommend.