Pulse Mason
Compose a four-beat building phrase. Choose a beat to edit, then tap its landing column. Beats drop SINGLE, TALL PAIR, SINGLE, WIDE PAIR in that order. Play executes all four drops, clearing full rows after each beat; later notes land in the changed gaps. Clear four rows within three phrases without blocking entry. You can reprogram between phrases. This is a turn-based sequencer, not a reaction timer.
Tap tiles, or use Tab and Enter. Arrow keys move board focus.
Challenge notes & source
This challenge has a reachable defeat condition described in the rules. A terminal result locks controls until Reset seed.
Four-beat lane programming makes each phrase a small plan whose earlier clears affect later shapes.
Original compact interpretation, not a recreation. Source study: Tetris on Beat. No source code, music or artwork copied.