According to the latest issue of Nintendo Power, Ubisoft has confirmed MotionPlus only. "It's a huge risk," said Red Steel 2 creative director Jason Vandenberghe. "We have no idea what the penetration rate for Wii MotionPlus will be. We assume high. We would like it to be high."
Sure you would. Vandenberghe went on to tell Nintendo Power that he would love to say the game was compatible with a regular controller, but that the gameplay just wasn't there.