Runner

Space, the up arrow, W, a tap, or a swipe up to jump. The down arrow, S, a swipe down, or the lower pad button to duck, and ducking is held rather than tapped. Blue slabs sit on the ground and want to be jumped. Amber bars hang at head height and want to be ducked, though a narrow one can be jumped instead once the corridor is moving quickly enough. Holding duck in the air drops you sooner, which is occasionally the only way to make the next gap. Nothing here is unclearable: the gap after every obstacle is measured against how long a jump lasts, so you are always back on the ground before the next thing arrives.