Common Modes
Why People Get This Wrong
People often assume that in "Ultra" mode, they must clear lines at a steady pace throughout the fixed time limit, but actually, it's all about maximizing score regardless of how quickly or slowly you play, as long as you hit the required score by the end. They overlook the fact that speed and efficiency aren't penalized here; rather, it’s about scoring potential in any given timeframe.
Official Verdict
Marathon / endless: play until top out.; Sprint: clear 40 lines as fast as possible.; Ultra: maximise score in a fixed time.