One of the highlights of any decent theme park is the gut-wrenching adrenaline rush of a well-designed rollercoaster.
There's nothing quite like the anticipation as the train of cars inches its way towards the first peak, nor the ecstatic terror as it hurtles around the track.
Of course, rollercoasters have to conform to strict safety regulations. It wouldn't do, for example, for one of the carts to detach itself from the track.
A key part of the challenge of 3D Rollercoaster Rush Underground is that its tracks suffer no such constraints: the train will happily soar free of its rails if you allow it to build sufficient speed on the inclines.
Your task, then, is to flirt with disaster by making the journey from start to finish as exciting as possible for your five passengers, without the coaster derailing and its precious cargo plummeting into oblivion.
Managing this via the deceptively simple controls - '6' accelerates while '4' applies the brakes - is made much more difficult by the inclusion of a variety of power-ups and obstacles spread along each track.
For example, fiendish placement of the Nitro Booster power-up before a sharp drop requires a swift use of the brakes, whilst red sections of track fall away as you pass over them, forcing you to maintain a steady velocity without losing control.
Pursuit of Happiness
Scoring in the standard Underground mode is based on a 'smile' meter, which is steadily filled by performing pant-wetting manoeuvres such as high speed loop-de-loops or controlled jumps. Achieve sufficient smiles for a three-star rating and you'll unlock further tracks.
Despite the occasional re-use of a trick or pitfall, there's a unique challenge to every one of the 60 levels that keeps things fresh.
Further value is added by an in-depth statistics page, which charts your progress and encourages you to go for the elusive five-star ratings on each level.
As if all that weren't enough, Digital Chocolate has included a brilliantly tense Danger mode. This extra mode features 25 tracks from Underground Mode, with the added spur of a steadily advancing wall of fire that chases your coaster across the screen. Move too slowly and you'll lose your passengers in the inferno, leading to an ignominious stab of the 'retry' button.
If 3D Rollercoaster Rush Underground has a weakness, it's to be found in the difficulty of a handful of the tracks. Occasionally you'll find yourself breezing through a level on the first attempt, while conversely it seems all but impossible to gain five stars on others.
Yet you'll find yourself forgiving such moments of frustration in the face of the sharp 3D graphics, the funky music, and the stylish presentation.