Stack the falling pieces. Fill a row to clear it; four at once is a Tetris.

Touch: swipe left or right to move, tap to rotate, drag down to soft drop, flick down to hard drop, tap the Hold slot to hold. Turn on Buttons in settings for an on-screen pad.

Keys: arrows move and soft drop, Up or X rotate, Z rotates back, C holds, Space hard drops, P pauses.

T-spins (twist a T into a slot), back-to-back Tetrises, combos and perfect clears all pay extra.

Modes: Marathon speeds up every 10 lines. Sprint races to 40 lines. Ultra is two minutes for max score. Daily is one seeded run a day. Zen never ends.