Pondoku: Binairo Takuzu Puzzle

A pond, two symbols, and one right answer. Pondoku is a gentle binairo puzzle (also called takuzu, or a binary sudoku) played on a pond, with cats. Fill the grid so every row and column holds the same number of crosses and cats, never three of the same in a row, and every = and x bridge between two cells is kept. Every level has exactly one answer and it can always be reached by logic, so there is never a reason to guess. HOW IT PLAYS One tap places a cross, two taps place the cat, hold to clear. That is the whole interface. The classic binary puzzle rules, plus the = and x signs, are enough to keep you busy for months. A NEW POND EVERY MORNING The Daily Pond is the same logic puzzle for everyone, generated from the date itself. Solve it, share the emoji grid, keep the streak. 300 LEVELS, FIFTEEN PONDS From gentle 4x4 boards that teach the rules to 10x10 boards that do not. Levels come in ponds of twenty, each with its own colour of water and its own crest. Finish one and the crest is yours; collect all sixty of its stars and it turns gold. Every level is checked to be solvable by logic alone before it ships. BUILT TO BE PLEASANT - No subscription. One small purchase removes the ads for good, and one rewarded ad buys thirty quiet minutes if you would rather not pay at all - One free hint on every level. Three hearts a level and no waiting for refills: run out and you start over, or watch one ad to refill them - Play offline, anywhere, with no account and no sign-up - A small download that stays small - Night theme for 2 AM, and a colour-blind mode that never relies on colour - Start with the cat, then earn the frog, the owl and the bee Quiet, cute, and just hard enough.