App of the Day: MotoHeroz

If RedLynx has one design lesson to teach to the world, it's this: you can make a game as hard as you like, as long as you give players a restart button that can be pressed at any time. It worked a charm in Trials, and it works again here.

It's important to note that it isn't quite instantaneous in MotoHeroz. Rather, it allows you half a second to reposition your thumbs back over the digital controls before you lurch off the start line once more. The timing is exquisite, the hallmark of an idea tested to the Nth degree.

The road from WiiWare to App Store isn't one that's commonly travelled, and MotoHeroz - a knockabout, physics-powered time-trialler that could reasonably be called Trials Jr. - has encountered a few bumps along the way. Gone is the slapstick chaos of the original's local multiplayer mode, while the single-player game has been repurposed to better fit its new format. Its touch-screen controls aren't a match for d-pad and buttons, but you knew that already. Besides, they're as close to the real thing as you're likely to find on iOS.

What you have, then, is a series of challenges spread across six themed environments, with a different vehicle to master in each. You'll bounce around desert stages in a dune buggy, pootle along woodland tracks in what looks like a souped-up tractor, and plough through heavy forest in a chibi tank that looks like a camouflaged rhino on wheels.

Tracks make even Trials HD's most outlandish courses seem conservative: you'll be launched by cannons, teleport from one side of the circuit to the other, and whizz round a concentric loop, powered by successive rocket pick-ups. Elsewhere you'll grab sticky wheels to cover tricky terrain and springs to clear gaps (or cut large sections of track, if you're savvy enough to know the perfect time to use them).

If all that suggests a lighter-hearted tone than RedLynx's most famous series, don't imagine the challenge is any less severe. Though you shouldn't have too much trouble finishing the courses - at times it actually helps to land upside-down, and you can right yourself with a shake if you're properly stuck - beating the times to three-star every stage proves a hefty long-term challenge. Each run sees you racing against ghosts representing the next star target and an online rival from a leaderboard position close to your own; if you don't beat the first, then you often have the consolation of having bettered another player's time.

The fun is soured slightly by an upgrade structure that requires you to pay in-game coins to boost acceleration, top speed and item boost. Though you'll pick up coins during each run (a hidden treasure chest on each stage provides a more substantial cash top-up) you either need to grind to make your vehicle competitive or pay a fee for a full upgrade.

But it's a minor niggle in a game that offers giddy thrills as frequently as it provokes stifled swears. It may be more gimmicky than Trials, but its physics and systems are every bit as robust. And when you invariably screw up, you know you're less than a second away from another shot at getting it right. It's another downloadable delight from a developer that takes having fun very seriously indeed.