Gamasutra reports on a talk at this year's Game Developers Conference by Mike Pagano, game producer for EA Mobile. Pagano brought up the difficulty in designing games for devices like the iPhone, where screen real estate is already limited, and a poorly implemented UI will result in players' thumbs and fingers blocking crucial parts of the action
"Pagano recommends button maps on the bottom of the screen, finger-sized, whenever possible, keeping interface away from the play area. 'Apple puts the main interactions on the very bottom of the screen,' he said. 'When you're unlocking for example, you know you can read what's on top. That's a huge thing, especially when you're designing games.' ... For accelerometer input, 'we did a lot of tuning with this SOB,' Pagano said, referring to Spore Origins. Pagano stressed that games using the accelerometer should have a mechanism to allow players to change their zero positions, effectively letting them play in a variety of positions — sitting in bed, leaning over the device, or holding it up. Early in development, Spore Origins had a touchscreen control scheme. 'Where it started to fall down was, again, sausage fingers.' Said Pagano. 'We made our decision right there to flip to the accelerometer.'"