When should you make a motion-sensing mobile game?
And perhaps more importantly, when shouldn't you?

There's no doubt that motion-sensing technology has got mobile games firms excited, as you'll know if you read the two previous parts of this feature – on its benefits, and their plans to make use of it.
However, it's important to think about the flipside too: when motion-sensing might not be a boon for mobile games – and in fact might be inappropriate. Chris Gibbs, from EA Mobile, explains one of the key design issues that will face anyone developing games using motion controls.
"It's really tough to see the screen when you are moving the phone around. So, unless you have pretty slow, gentle movements, you have to ensure the player is doing something that doesn't rely on immediate visual feedback," he says.
"This is a pretty big barrier that the Wii doesn't suffer from. Basically you need to let the player know what movement is required, then have them carry the movement out, and after the movement is completed, use the screen to show the outcome."
Other publishers agree that the 'not being able to see the screen' thing could be crucial – which rather goes against the flurry of motion bowling games we've seen so far.
"I believe games like bowling will be hard to pull off, since gamers will want to see the mobile screen while playing," says Wilhelm Taht of RealArcade.
Meanwhile, Paul Maglione of Vivendi Games Mobile backs him up. "These games, like bowling, darts and golf sound like a great use of the technology, but frankly make you look like a gibbon on the tube," he says.
"We're staying away from those ones. But games requiring subtle directional control, like driving, tilt-ball, snowboarding and other glide sports, are really enhanced by motion-sensing. There is a puzzle game we are working on which will be a great use of the technology..."
Maglione also says games that require specific key inputs won't be as suitable for motion controls – for example strategy games. In that he's backed up by Chris White of Glu Mobile, who also highlights the fact that publishers need to make the most of motion, rather than making it awkwardly replace existing systems.
"Motion-sensing isn't as precise as traditional control mechanisms yet, so games that require precision controls won't fare well," he says.
"However, it's up to developers like Glu to design games that maximise the control methods that are available rather than trying to retrofit existing titles. Our Get Cookin' uses dynamic and short moves, which is perfect for this generation of motion-sensing technology."
One problem for using motion-sensing may be when it's poorly incorporated or oversensitive, particularly on phones with regular keypads, where motion and traditional button presses are combined.
"Combining motion sensing with complicated button controls won't work," says Andrew Stein of PopCap Games. "Accidentally tilting the phone in an undesired direction while trying to push buttons is only going to frustrate users."
In other words, simplicity rules. What about phones without buttons though – touchscreen handsets such as the iPhone and its ever-growing list of rivals? Howard Tomlinson, of Astraware, thinks this will be a key area of innovation.
"It will be interesting to see the different kinds of controls that are created using the touchscreen, perhaps in combination with motion sensing," he says. It's this combination of motion AND touch that's got developers really excited (and explains much of the kerfuffle around the upcoming iPhone App Store).
Motion-sensing is like any new technology, in other words. Developers and publishers will rush to make use of it because it's the hot new thing, without always considering whether it's actually appropriate.
"There will not be a huge number of games out there that are actually suitable for motion controls," says Taht. "You are bound to see many that shouldn't actually have been made!"