Sink a heavier crypt stone into a neighbour. Equals cancel; a heavier stone leaves the difference. Clear every stone before you run out of moves.
Stones on the crypt floor
Each stone carries a weight. Tap one to select it, then tap an orthogonal neighbour that is equal or lighter. Equal weights cancel and both vanish. A heavier stone sinks into the lighter one and leaves only the difference behind.
Valid neighbours light up with the value that would remain, so you can read the sink before you commit.
Plan the chain, avoid the lone stone
Every sink removes one stone and either clears or shrinks another. The order matters: a careless annihilation can isolate a single stone with nowhere to go, and the floor is lost. Undo steps back; Restart reloads the board.
Five floors grow from a single pair to a 3×3 gate. The early boards teach cancel and difference; the last one asks for a seven-sink line within nine moves.
When the floor is clear, tap Next. On the last floor, Again wraps back to the first.
