As an iOS Developer, this is a setting we can control and set to lock a specific rotation. We have 4 checkboxes, which are, portrait, upside down, landscape left and landscape right. In theory, you could lock it to be only upside down. In this case, this seems to be a decision made by the developers of Jetpack Joyride to lock it to a landscape orientation, presumably to stop it from automatically rotating on accident when playing the game. (Which would play a whole animation, therefore stopping the game flow) As a long time iOS fan and developer, I do however not see any reason why they shouldn't have a landscape mode for lock orientation, so your point still stands. But I just wanted to make this case clear.