Kwiff

Kwiff
Kwiff is the classic Nikoli "Magnets" logic puzzle, reskinned as a bench
of electromagnet panels waiting to be wired. Every panel arrives pre-cut into
domino-shaped slots. Tap a slot to cycle it through a "+/-" charge, a "-/+"
charge, or blank - nothing else. Numbers along the top and bottom name how
many "+" and "-" ends each column must carry; numbers on the left and right
do the same for each row. The one hard rule never bends: two identical poles
can never sit side by side, even across a slot boundary, or the circuit
shorts and glows red. There is no timer trap and no random deal - every one
of the twenty panels is built by placing a legal solution first and reading
the clues back off it, so a real answer always exists, and a small solver
checks every panel before it ships. Panels grow from a compact four-by-four
bench test up to a dense ten-by-ten mains board as you climb the levels, so
what you are training is pattern-holding and constraint-tracing under more
moving parts, not reflexes. No purchase ever solves a panel for you; coins
only mark the panels you have already wired clean.