Tricolor Descent

Clear at least 18 tiles AND trigger a two-wave cascade. Cycle or reverse each falling color column. Gravity after a match can line up the next wave. A wave clears every horizontal/vertical triple simultaneously. Remaining tiles fall, then matching runs repeat. Tile quota alone is not victory: best cascade must be at least 2 waves. Aiming, reordering and rejected drops cost nothing. Undo and restart recover mistakes. No timer.