Galaxies

Galaxies (also known as Tentai Show) is an elegant and visually satisfying logic puzzle where you divide a rectangular grid into rotationally symmetric regions, each centered on a given dot—representing the “core” of a galaxy. Every cell in the grid must belong to exactly one galaxy, and each galaxy must be symmetric around its central dot: if you rotate the region 180 degrees about that dot, it looks exactly the same.

The puzzle starts with a grid containing scattered dots. Your task is to draw borders between cells to form galaxies that:

• Are 180° rotationally symmetric around their central dot.
• Do not overlap, Cover the entire grid with no gaps.
• Contain only one dot, which must be at the exact center of symmetry.

Despite its simple rules, Galaxies offers a rich logical challenge. Solving it involves analyzing how symmetry constraints propagate through the grid—often forcing the shape of a galaxy based on the position of its dot and nearby boundaries. Corner and edge dots, for example, immediately imply certain cell inclusions, while closely spaced dots limit each other’s possible regions.

Galaxies combines spatial reasoning, symmetry intuition, and deductive logic into a uniquely calming yet stimulating experience.

To play Galaxies Puzzle, start by selecting a puzzle type and size from the "Type" menu. Click "New" to generate a new puzzle.

Draw lines along the grid edges to divide the grid into connected regions of squares.

Every region must have 180° rotational symmetry, contain exactly one dot at its center, and have no internal lines separating any of its squares. Regions meeting all these conditions will be automatically highlighted.

Click on a grid edge to add or remove a line.

Right-click on a dot and drag the mouse to place an arrow in a grid square pointing toward that dot—indicating that you believe the square belongs to the same region as the dot.

To move an existing arrow, right-drag it; to delete it, drag it off the edge of the grid.