About This Game
MoonSun adapts the binary grid mechanic (also known as Takuzu or Binero), a logic puzzle format that recently found renewed popularity through LinkedIn's daily puzzle feature named "Tango". The symbols were swapped for suns and moons to feel more familiar and kid-friendly, but the core ruleset is the same classic format underneath.
Like the other puzzle games on Dodolanan, only the mechanic was adopted as a logic-puzzle format — the boards, the generator, and the visuals here were built from scratch, not copied from anywhere else.
How to Play
Fill every empty square with a sun or a moon (tap repeatedly to cycle: empty → sun → moon → empty) until the whole board is filled and satisfies four rules at once: every row and column must contain an equal number of suns and moons; no three matching symbols may appear in a row, whether horizontally or vertically; no two rows may be identical to each other, and likewise for columns; and the marks on cell borders ("=" meaning the two cells must match, "×" meaning they must differ) must be respected.
Early levels (4×4 boards) reveal a few pre-filled squares so the puzzle doesn't feel intimidating; later levels (6×6 boards) give only a handful of starting clues, requiring longer chains of deduction. Rule violations are highlighted red the moment they happen, and Hint is always available — every board is guaranteed to have exactly one solution, so Hint always reveals a genuinely correct square.
Strategy & Tips
This puzzle is pure logical deduction — no real guessing is ever needed if you apply the patterns below systematically.
- The "no three in a row" rule cuts both ways: if two adjacent squares already match (say, two suns side by side), the square right next to them must be a moon. And if an empty square is sandwiched between two matching symbols on either side (or above and below), that middle square must be the opposite symbol.
- Count each row and column as you go: once one symbol reaches half the length of a row or column (e.g. 3 suns in a row of length 6), every remaining empty square in that row or column must automatically be the other symbol.
- Follow chains of "=" and "×" marks like equations: if A matches B, and B differs from C, then A must differ from C too — these marks often link together and unlock several squares at once.
- Work on whichever row or column has the fewest empty squares left first — the fewer squares remaining, the faster the rules above force a single answer.
- If you're stuck, lean on the "no duplicate rows/columns" rule: if a nearly-finished row would become identical to an already-completed row by filling its last square one way, the answer has to be the other way instead.