iPad2 (& Safari) seem to drop my game's frame rate from 60ps to 30fps max. 30fps is still ok, so I tried to resolve the move/speed issue by using delta time between frames, at the beginning of every update routine: var deltaTime = game.time.elapsed; ...and applying deltaTime to x/y movements. This just caused image & sprite movements to double their speed in iPad. Game tweens seemed to suffer the same problem. However P2 physics seem to work ok in all devices. After searching and testing, I found a solution for delta time: var deltaTime = game.time.physicsElapsed; And for tweens, setting this parameter did the trick: Tween.frameBased = true; ...although duration seem to be still in milliseconds, not in frames, as the documentation states. I'm wondering where Phaser.Time.elapsed is needed, when Phaser.Time.physicsElapsed does the trick so much better?!