Cipherwell
An old shaft, lined the whole way down with number-stones. You go deeper by ciphering: press a stone and drag, and the path you trace reads as one expression — number, operator, number, on and on. Let go when it equals the figure the well is asking for. Let go on anything else and the stones still shatter, you still spend the move, and your streak dies — but the board is different now, and sometimes that is exactly what you needed. Sixty levels down five strata, from single-digit sums in daylight to seven-stone chains with the order of operations in force and holes in the wall. Progress saves in your browser on this device.
Controls
Draw a chain
Press a number stone and drag through its neighbours — eight ways, diagonals included. The path has to alternate number, operator, number.
Let go
Releasing is the only thing that spends a move. Until then nothing is committed, and the running total is printed above the board the whole time.
Undo a step
Drag back over the last stone to drop it. That is free. Release outside the board, press Esc or right-click to throw the whole chain away.
Tap instead
Tap a stone rather than dragging and the chain stays open: tap on to extend, tap the last stone again to release.
Keyboard
←→↑↓ move · Space adds a stone · Enter releases · Backspace undoes
Shortcuts
H asks the well for a hint — it costs the clean bonus · R restarts the level · M toggles sound
Drag with a finger exactly as with a mouse — it is the same gesture, and dragging back undoes. Turn sideways or tap Fullscreen for a bigger board.