Survey Stack

Complete the survey stack by placing one horizontal slab, then solving and clearing all three occupied rows. During Build, tap a column to aim the two-cell slab and Drop it into the landing ghost. Survey mode then reveals certified safe clues. Each number counts mines in all eight neighboring occupied cells; there are two mines in total. Reveal opens a safe cell or detonates a mine. Flag marks an unrevealed cell. Chord on a revealed number opens its remaining neighbors only when the adjacent flag count matches; a mistaken flag can make that chord dangerous. A full row clears only when every safe cell is revealed and every mine correctly flagged, shifting higher rows down and updating clues. No mine location is stated outright: combine the visible numbers. Keyboard: Tab and Enter/Space operate buttons; R restarts.